diff --git a/changelog/refactor-affirm-payment-method-definition b/changelog/refactor-affirm-payment-method-definition
new file mode 100644
index 00000000000..38ee5edaa74
--- /dev/null
+++ b/changelog/refactor-affirm-payment-method-definition
@@ -0,0 +1,5 @@
+Significance: patch
+Type: dev
+Comment: chore: migrate from Affirm_Payment_Method:class to AffirmDefinition
+
+
diff --git a/includes/class-duplicates-detection-service.php b/includes/class-duplicates-detection-service.php
index 446275aad5a..4ae5af6a13a 100644
--- a/includes/class-duplicates-detection-service.php
+++ b/includes/class-duplicates-detection-service.php
@@ -12,7 +12,6 @@
 }
 
 use WC_Payments;
-use WCPay\Payment_Methods\Affirm_Payment_Method;
 use WCPay\Payment_Methods\Afterpay_Payment_Method;
 use WCPay\Payment_Methods\Bancontact_Payment_Method;
 use WCPay\Payment_Methods\Becs_Payment_Method;
@@ -106,7 +105,6 @@ private function search_for_additional_payment_methods() {
 			'ideal'      => Ideal_Payment_Method::PAYMENT_METHOD_STRIPE_ID,
 			'becs'       => Becs_Payment_Method::PAYMENT_METHOD_STRIPE_ID,
 			'eps'        => Eps_Payment_Method::PAYMENT_METHOD_STRIPE_ID,
-			'affirm'     => Affirm_Payment_Method::PAYMENT_METHOD_STRIPE_ID,
 			'afterpay'   => Afterpay_Payment_Method::PAYMENT_METHOD_STRIPE_ID,
 			'clearpay'   => Afterpay_Payment_Method::PAYMENT_METHOD_STRIPE_ID,
 			'klarna'     => Klarna_Payment_Method::PAYMENT_METHOD_STRIPE_ID,
diff --git a/includes/class-wc-payment-gateway-wcpay.php b/includes/class-wc-payment-gateway-wcpay.php
index 30cd2730d79..fc9b4fb1cae 100644
--- a/includes/class-wc-payment-gateway-wcpay.php
+++ b/includes/class-wc-payment-gateway-wcpay.php
@@ -56,7 +56,6 @@
 use WCPay\Tracker;
 use WCPay\Internal\Service\Level3Service;
 use WCPay\Internal\Service\OrderService;
-use WCPay\Payment_Methods\Affirm_Payment_Method;
 use WCPay\Payment_Methods\Afterpay_Payment_Method;
 use WCPay\Payment_Methods\Bancontact_Payment_Method;
 use WCPay\Payment_Methods\Becs_Payment_Method;
diff --git a/includes/class-wc-payments.php b/includes/class-wc-payments.php
index 35c1ac8aadc..ca805fbba8f 100644
--- a/includes/class-wc-payments.php
+++ b/includes/class-wc-payments.php
@@ -29,7 +29,6 @@
 use WCPay\WooPay\WooPay_Utilities;
 use WCPay\WooPay\WooPay_Order_Status_Sync;
 use WCPay\Payment_Methods\Link_Payment_Method;
-use WCPay\Payment_Methods\Affirm_Payment_Method;
 use WCPay\Payment_Methods\Afterpay_Payment_Method;
 use WCPay\Session_Rate_Limiter;
 use WCPay\Database_Cache;
@@ -438,7 +437,6 @@ public static function init() {
 		include_once __DIR__ . '/payment-methods/class-becs-payment-method.php';
 		include_once __DIR__ . '/payment-methods/class-eps-payment-method.php';
 		include_once __DIR__ . '/payment-methods/class-link-payment-method.php';
-		include_once __DIR__ . '/payment-methods/class-affirm-payment-method.php';
 		include_once __DIR__ . '/payment-methods/class-afterpay-payment-method.php';
 		include_once __DIR__ . '/payment-methods/class-klarna-payment-method.php';
 		include_once __DIR__ . '/payment-methods/class-multibanco-payment-method.php';
@@ -586,7 +584,6 @@ public static function init() {
 			Becs_Payment_Method::class,
 			Eps_Payment_Method::class,
 			Link_Payment_Method::class,
-			Affirm_Payment_Method::class,
 			Afterpay_Payment_Method::class,
 			Klarna_Payment_Method::class,
 			Multibanco_Payment_Method::class,
diff --git a/includes/payment-methods/Configs/Definitions/AffirmDefinition.php b/includes/payment-methods/Configs/Definitions/AffirmDefinition.php
new file mode 100644
index 00000000000..6a212d02015
--- /dev/null
+++ b/includes/payment-methods/Configs/Definitions/AffirmDefinition.php
@@ -0,0 +1,250 @@
+<?php
+/**
+ * Affirm Payment Method Definition
+ *
+ * @package WCPay\PaymentMethods\Configs\Definitions
+ */
+
+namespace WCPay\PaymentMethods\Configs\Definitions;
+
+use WCPay\PaymentMethods\Configs\Interfaces\PaymentMethodDefinitionInterface;
+use WCPay\PaymentMethods\Configs\Constants\PaymentMethodCapability;
+use WCPay\Constants\Country_Code;
+use WCPay\Constants\Currency_Code;
+use WCPay\PaymentMethods\Configs\Utils\PaymentMethodUtils;
+
+/**
+ * Class implementing the Affirm payment method definition.
+ */
+class AffirmDefinition implements PaymentMethodDefinitionInterface {
+
+	/**
+	 * Get the internal ID for the payment method
+	 *
+	 * @return string
+	 */
+	public static function get_id(): string {
+		return 'affirm';
+	}
+
+	/**
+	 * Get the keywords for the payment method. These are used by the duplicates detection service.
+	 *
+	 * @return string[]
+	 */
+	public static function get_keywords(): array {
+		return [ 'affirm' ];
+	}
+
+	/**
+	 * Get the Stripe payment method ID
+	 *
+	 * @return string
+	 */
+	public static function get_stripe_id(): string {
+		return PaymentMethodUtils::get_stripe_id( self::get_id() );
+	}
+
+	/**
+	 * Get the customer-facing title of the payment method
+	 *
+	 * @param string|null $account_country Optional. The merchant's account country.
+	 *
+	 * @return string
+	 */
+	public static function get_title( ?string $account_country = null ): string {
+		return __( 'Affirm', 'woocommerce-payments' );
+	}
+
+	/**
+	 * Get the title of the payment method for the settings page.
+	 *
+	 * @param string|null $account_country Optional. The merchant's account country.
+	 *
+	 * @return string
+	 */
+	public static function get_settings_label( ?string $account_country = null ): string {
+		return self::get_title( $account_country );
+	}
+
+	/**
+	 * Get the customer-facing description of the payment method
+	 *
+	 * @param string|null $account_country Optional. The merchant's account country.
+	 * @return string
+	 */
+	public static function get_description( ?string $account_country = null ): string {
+		return __( 'Allow customers to pay over time with Affirm.', 'woocommerce-payments' );
+	}
+
+	/**
+	 * Is the payment method a BNPL (Buy Now Pay Later) payment method?
+	 *
+	 * @return boolean
+	 */
+	public static function is_bnpl(): bool {
+		return PaymentMethodUtils::is_bnpl( self::get_capabilities() );
+	}
+
+	/**
+	 * Is the payment method a reusable payment method?
+	 *
+	 * @return boolean
+	 */
+	public static function is_reusable(): bool {
+		return PaymentMethodUtils::is_reusable( self::get_capabilities() );
+	}
+
+	/**
+	 * Does the payment method accept only domestic payments?
+	 *
+	 * @return boolean
+	 */
+	public static function accepts_only_domestic_payments(): bool {
+		return PaymentMethodUtils::accepts_only_domestic_payments( self::get_capabilities() );
+	}
+
+	/**
+	 * Does the payment method allow manual capture?
+	 *
+	 * @return boolean
+	 */
+	public static function allows_manual_capture(): bool {
+		return PaymentMethodUtils::allows_manual_capture( self::get_capabilities() );
+	}
+
+	/**
+	 * Get the list of supported currencies
+	 *
+	 * @return string[] Array of currency codes
+	 */
+	public static function get_supported_currencies(): array {
+		return [ Currency_Code::UNITED_STATES_DOLLAR, Currency_Code::CANADIAN_DOLLAR ];
+	}
+
+	/**
+	 * Get the list of supported countries
+	 *
+	 * @return string[] Array of country codes
+	 */
+	public static function get_supported_countries(): array {
+		return [ Country_Code::UNITED_STATES, Country_Code::CANADA ];
+	}
+
+	/**
+	 * Get the payment method capabilities
+	 *
+	 * @return string[]
+	 */
+	public static function get_capabilities(): array {
+		return [
+			PaymentMethodCapability::REFUNDS,
+			PaymentMethodCapability::MULTI_CURRENCY,
+			PaymentMethodCapability::BNPL,
+			PaymentMethodCapability::DOMESTIC_PAYMENTS_ONLY,
+		];
+	}
+
+	/**
+	 * Get the URL for the payment method's icon
+	 *
+	 * @param string|null $account_country Optional. The merchant's account country.
+	 *
+	 * @return string
+	 */
+	public static function get_icon_url( ?string $account_country = null ): string {
+		return plugins_url( 'assets/images/payment-methods/affirm-logo.svg', WCPAY_PLUGIN_FILE );
+	}
+
+	/**
+	 * Get the URL for the payment method's dark mode icon
+	 *
+	 * @param string|null $account_country Optional. The merchant's account country.
+	 *
+	 * @return string Returns regular icon URL if no dark mode icon exists
+	 */
+	public static function get_dark_icon_url( ?string $account_country = null ): string {
+		return plugins_url( 'assets/images/payment-methods/affirm-logo-dark.svg', WCPAY_PLUGIN_FILE );
+	}
+
+	/**
+	 * Get the URL for the payment method's settings icon
+	 *
+	 * @param string|null $account_country Optional. The merchant's account country.
+	 *
+	 * @return string
+	 */
+	public static function get_settings_icon_url( ?string $account_country = null ): string {
+		return plugins_url( 'assets/images/payment-methods/affirm-badge.svg', WCPAY_PLUGIN_FILE );
+	}
+
+	/**
+	 * Get the testing instructions for the payment method
+	 *
+	 * @param string $account_country The merchant's account country.
+	 * @return string HTML string containing testing instructions
+	 */
+	public static function get_testing_instructions( string $account_country ): string {
+		return '';
+	}
+
+	/**
+	 * Get the currency limits for the payment method
+	 *
+	 * @return array<string,array<string,array{min:int,max:int}>>
+	 */
+	public static function get_limits_per_currency(): array {
+		return \WC_Payments_Utils::get_bnpl_limits_per_currency( self::get_id() );
+	}
+
+	/**
+	 * Whether this payment method is available for the given currency and country
+	 *
+	 * @param string $currency The currency code to check.
+	 * @param string $account_country The merchant's account country.
+	 *
+	 * @return bool
+	 */
+	public static function is_available_for( string $currency, string $account_country ): bool {
+		if ( ! PaymentMethodUtils::is_available_for( self::get_supported_currencies(), self::get_supported_countries(), $currency, $account_country ) ) {
+			return false;
+		}
+
+		return true;
+	}
+
+	/**
+	 * Whether this payment method should be enabled by default
+	 *
+	 * @return bool
+	 */
+	public static function is_enabled_by_default(): bool {
+		return false;
+	}
+
+	/**
+	 * Get the minimum amount for this payment method for a given currency and country
+	 *
+	 * @param string $currency The currency code.
+	 * @param string $country The country code.
+	 *
+	 * @return int|null The minimum amount or null if no minimum.
+	 */
+	public static function get_minimum_amount( string $currency, string $country ): ?int {
+		$limits = self::get_limits_per_currency();
+		return $limits[ $currency ][ $country ]['min'] ?? null;
+	}
+
+	/**
+	 * Get the maximum amount for this payment method for a given currency and country
+	 *
+	 * @param string $currency The currency code.
+	 * @param string $country The country code.
+	 *
+	 * @return int|null The maximum amount or null if no maximum.
+	 */
+	public static function get_maximum_amount( string $currency, string $country ): ?int {
+		$limits = self::get_limits_per_currency();
+		return $limits[ $currency ][ $country ]['max'] ?? null;
+	}
+}
diff --git a/includes/payment-methods/Configs/Registry/PaymentMethodDefinitionRegistry.php b/includes/payment-methods/Configs/Registry/PaymentMethodDefinitionRegistry.php
index da70308275e..9c0c326c965 100644
--- a/includes/payment-methods/Configs/Registry/PaymentMethodDefinitionRegistry.php
+++ b/includes/payment-methods/Configs/Registry/PaymentMethodDefinitionRegistry.php
@@ -7,6 +7,7 @@
 
 namespace WCPay\PaymentMethods\Configs\Registry;
 
+use WCPay\PaymentMethods\Configs\Definitions\AffirmDefinition;
 use WCPay\PaymentMethods\Configs\Definitions\AlipayDefinition;
 use WCPay\PaymentMethods\Configs\Interfaces\PaymentMethodDefinitionInterface;
 
@@ -30,6 +31,7 @@ class PaymentMethodDefinitionRegistry {
 	private $available_definitions = [
 		// Add new payment method definitions here.
 		AlipayDefinition::class,
+		AffirmDefinition::class,
 	];
 
 	/**
diff --git a/includes/payment-methods/class-affirm-payment-method.php b/includes/payment-methods/class-affirm-payment-method.php
deleted file mode 100644
index 05c6aa8609e..00000000000
--- a/includes/payment-methods/class-affirm-payment-method.php
+++ /dev/null
@@ -1,85 +0,0 @@
-<?php
-/**
- * Class Affirm_Payment_Method
- *
- * @package WCPay\Payment_Methods
- */
-
-namespace WCPay\Payment_Methods;
-
-use WC_Payments_Token_Service;
-use WC_Payments_Utils;
-use WCPay\Constants\Country_Code;
-use WCPay\Constants\Currency_Code;
-
-/**
- * Affirm Payment Method class extending UPE base class
- */
-class Affirm_Payment_Method extends UPE_Payment_Method {
-
-	const PAYMENT_METHOD_STRIPE_ID = 'affirm';
-
-	/**
-	 * Constructor for Affirm payment method
-	 *
-	 * @param WC_Payments_Token_Service $token_service Token class instance.
-	 */
-	public function __construct( $token_service ) {
-		parent::__construct( $token_service );
-		$this->stripe_id                    = self::PAYMENT_METHOD_STRIPE_ID;
-		$this->is_reusable                  = false;
-		$this->is_bnpl                      = true;
-		$this->icon_url                     = plugins_url( 'assets/images/payment-methods/affirm-logo.svg', WCPAY_PLUGIN_FILE );
-		$this->dark_icon_url                = plugins_url( 'assets/images/payment-methods/affirm-logo-dark.svg', WCPAY_PLUGIN_FILE );
-		$this->currencies                   = [ Currency_Code::UNITED_STATES_DOLLAR, Currency_Code::CANADIAN_DOLLAR ];
-		$this->accept_only_domestic_payment = true;
-		$this->limits_per_currency          = WC_Payments_Utils::get_bnpl_limits_per_currency( self::PAYMENT_METHOD_STRIPE_ID );
-		$this->countries                    = [ Country_Code::UNITED_STATES, Country_Code::CANADA ];
-	}
-
-	/**
-	 * Returns payment method title
-	 *
-	 * @param string|null $account_country Country of merchants account.
-	 * @param array|false $payment_details Optional payment details from charge object.
-	 *
-	 * @return string
-	 */
-	public function get_title( ?string $account_country = null, $payment_details = false ) {
-		return __( 'Affirm', 'woocommerce-payments' );
-	}
-
-	/**
-	 * Returns testing credentials to be printed at checkout in test mode.
-	 *
-	 * @param string $account_country The country of the account.
-	 * @return string
-	 */
-	public function get_testing_instructions( string $account_country ) {
-		return '';
-	}
-
-	/**
-	 * Returns payment method description for the settings page.
-	 *
-	 * @param string|null $account_country Country of merchants account.
-	 *
-	 * @return string
-	 */
-	public function get_description( ?string $account_country = null ) {
-		return __(
-			'Allow customers to pay over time with Affirm.',
-			'woocommerce-payments'
-		);
-	}
-
-	/**
-	 * Returns payment method settings icon.
-	 *
-	 * @param string|null $account_country Country of merchants account.
-	 * @return string
-	 */
-	public function get_settings_icon_url( ?string $account_country = null ) {
-		return plugins_url( 'assets/images/payment-methods/affirm-badge.svg', WCPAY_PLUGIN_FILE );
-	}
-}
diff --git a/tests/unit/payment-methods/test-class-upe-payment-gateway.php b/tests/unit/payment-methods/test-class-upe-payment-gateway.php
index d37033667e8..2fe907ca880 100644
--- a/tests/unit/payment-methods/test-class-upe-payment-gateway.php
+++ b/tests/unit/payment-methods/test-class-upe-payment-gateway.php
@@ -254,7 +254,6 @@ public function set_up() {
 			Sepa_Payment_Method::class,
 			Becs_Payment_Method::class,
 			Link_Payment_Method::class,
-			Affirm_Payment_Method::class,
 			Afterpay_Payment_Method::class,
 		];
 
diff --git a/tests/unit/payment-methods/test-class-upe-payment-method.php b/tests/unit/payment-methods/test-class-upe-payment-method.php
index bb986dd2c97..484a6e48e63 100644
--- a/tests/unit/payment-methods/test-class-upe-payment-method.php
+++ b/tests/unit/payment-methods/test-class-upe-payment-method.php
@@ -81,7 +81,6 @@ public function set_up() {
 			Sepa_Payment_Method::class,
 			Becs_Payment_Method::class,
 			Link_Payment_Method::class,
-			Affirm_Payment_Method::class,
 			Afterpay_Payment_Method::class,
 			Klarna_Payment_Method::class,
 		];
diff --git a/tests/unit/test-class-wc-payment-gateway-wcpay.php b/tests/unit/test-class-wc-payment-gateway-wcpay.php
index 02fb62b9f94..f4b0a40b733 100644
--- a/tests/unit/test-class-wc-payment-gateway-wcpay.php
+++ b/tests/unit/test-class-wc-payment-gateway-wcpay.php
@@ -27,7 +27,6 @@
 use WCPay\Internal\Service\Level3Service;
 use WCPay\Internal\Service\OrderService;
 use WCPay\Payment_Information;
-use WCPay\Payment_Methods\Affirm_Payment_Method;
 use WCPay\Payment_Methods\Afterpay_Payment_Method;
 use WCPay\Payment_Methods\Bancontact_Payment_Method;
 use WCPay\Payment_Methods\Becs_Payment_Method;
@@ -3985,7 +3984,6 @@ private function init_payment_methods() {
 			Becs_Payment_Method::class,
 			Eps_Payment_Method::class,
 			Link_Payment_Method::class,
-			Affirm_Payment_Method::class,
 			Afterpay_Payment_Method::class,
 			Klarna_Payment_Method::class,
 			Grabpay_Payment_Method::class,