diff --git a/CHANGELOG.md b/CHANGELOG.md
index b39ab1f2d..44df305cb 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,7 +10,8 @@ _None_
 
 ### New Features
 
-_None_
+- Add new `buildkite_annotate` action to add/remove annotations from the current build. [#442]
+- Add new `buildkite_metadata` action to set/get metadata from the current build. [#442]
 
 ### Bug Fixes
 
@@ -24,7 +25,7 @@ _None_
 
 ### New Features
 
-- Added Mac support to all `common` actions and any relevant `ios` actions [#439]
+- Add Mac support to all `common` actions and any relevant `ios` actions [#439]
 
 ## 6.2.0
 
diff --git a/lib/fastlane/plugin/wpmreleasetoolkit/actions/common/buildkite_annotate_action.rb b/lib/fastlane/plugin/wpmreleasetoolkit/actions/common/buildkite_annotate_action.rb
new file mode 100644
index 000000000..2b0b2f34f
--- /dev/null
+++ b/lib/fastlane/plugin/wpmreleasetoolkit/actions/common/buildkite_annotate_action.rb
@@ -0,0 +1,85 @@
+module Fastlane
+  module Actions
+    class BuildkiteAnnotateAction < Action
+      def self.run(params)
+        message = params[:message]
+        context = params[:context]
+        style = params[:style]
+
+        if message.nil?
+          # Delete an annotation, but swallow the error if the annotation didn't exist — to avoid having
+          # this action failing or printing a red log for no good reason — hence the `|| true`
+          ctx_param = "--context #{context.shellescape}" unless context.nil?
+          sh("buildkite-agent annotation remove #{ctx_param} || true")
+        else
+          # Add new annotation using `buildkite-agent`
+          extra_params = {
+            context: context,
+            style: style
+          }.compact.flat_map { |k, v| ["--#{k}", v] }
+          sh('buildkite-agent', 'annotate', *extra_params, params[:message])
+        end
+      end
+
+      #####################################################
+      # @!group Documentation
+      #####################################################
+
+      def self.description
+        'Add or remove annotations to the current Buildkite build'
+      end
+
+      def self.details
+        <<~DETAILS
+          Add or remove annotations to the current Buildkite build.
+
+          Has to be run on a CI job (where a `buildkite-agent` is running), e.g. typically by a lane
+          that is triggered as part of a Buildkite CI step.
+
+          See https://buildkite.com/docs/agent/v3/cli-annotate
+        DETAILS
+      end
+
+      def self.available_options
+        [
+          FastlaneCore::ConfigItem.new(
+            key: :context,
+            env_name: 'BUILDKITE_ANNOTATION_CONTEXT',
+            description: 'The context of the annotation used to differentiate this annotation from others',
+            type: String,
+            optional: true
+          ),
+          FastlaneCore::ConfigItem.new(
+            key: :style,
+            env_name: 'BUILDKITE_ANNOTATION_STYLE',
+            description: 'The style of the annotation (`success`, `info`, `warning` or `error`)',
+            type: String,
+            optional: true,
+            verify_block: proc do |value|
+              valid_values = %w[success info warning error]
+              next if value.nil? || valid_values.include?(value)
+
+              UI.user_error!("Invalid value `#{value}` for parameter `style`. Valid values are: #{valid_values.join(', ')}")
+            end
+          ),
+          FastlaneCore::ConfigItem.new(
+            key: :message,
+            description: 'The message to use in the new annotation. Supports GFM-Flavored Markdown. ' \
+            + 'If message is nil, any existing annotation with the provided context will be deleted',
+            type: String,
+            optional: true,
+            default_value: nil # nil message = delete existing annotation if any
+          ),
+        ]
+      end
+
+      def self.authors
+        ['Automattic']
+      end
+
+      def self.is_supported?(platform)
+        true
+      end
+    end
+  end
+end
diff --git a/lib/fastlane/plugin/wpmreleasetoolkit/actions/common/buildkite_metadata_action.rb b/lib/fastlane/plugin/wpmreleasetoolkit/actions/common/buildkite_metadata_action.rb
new file mode 100644
index 000000000..15d182849
--- /dev/null
+++ b/lib/fastlane/plugin/wpmreleasetoolkit/actions/common/buildkite_metadata_action.rb
@@ -0,0 +1,67 @@
+module Fastlane
+  module Actions
+    class BuildkiteMetadataAction < Action
+      def self.run(params)
+        # Set/Add new metadata values
+        params[:set]&.each do |key, value|
+          sh('buildkite-agent', 'meta-data', 'set', key.to_s, value.to_s)
+        end
+
+        # Return value of existing metadata key
+        sh('buildkite-agent', 'meta-data', 'get', params[:get].to_s) unless params[:get].nil?
+      end
+
+      #####################################################
+      # @!group Documentation
+      #####################################################
+
+      def self.description
+        'Set/Get metadata to the current Buildkite build'
+      end
+
+      def self.details
+        <<~DETAILS
+          Set and/or get metadata to the current Buildkite build.
+
+          Has to be run on a CI job (where a `buildkite-agent` is running), e.g. typically by a lane
+          that is triggered as part of a Buildkite CI step.
+
+          See https://buildkite.com/docs/agent/v3/cli-meta-data
+        DETAILS
+      end
+
+      def self.available_options
+        [
+          FastlaneCore::ConfigItem.new(
+            key: :set,
+            env_name: 'BUILDKITE_METADATA_SET',
+            description: 'The hash of key/value pairs of the meta-data to set',
+            type: Hash,
+            optional: true,
+            default_value: nil
+          ),
+          FastlaneCore::ConfigItem.new(
+            key: :get,
+            env_name: 'BUILDKITE_METADATA_GET',
+            description: 'The key of the metadata to get the value of',
+            type: String,
+            optional: true,
+            default_value: nil
+          ),
+        ]
+      end
+
+      def self.return_value
+        'The value of the Buildkite metadata corresponding to the provided `get` key. `nil` if no `get` parameter was provided.'
+      end
+
+      def self.authors
+        ['Automattic']
+      end
+
+      def self.is_supported?(platform)
+        true
+      end
+    end
+  end
+end
diff --git a/spec/buildkite_annotate_action_spec.rb b/spec/buildkite_annotate_action_spec.rb
new file mode 100644
index 000000000..f042acee7
--- /dev/null
+++ b/spec/buildkite_annotate_action_spec.rb
@@ -0,0 +1,82 @@
+require 'spec_helper'
+
+describe Fastlane::Actions::BuildkiteAnnotateAction do
+  describe '`style` parameter validation' do
+    it 'errors if we use an invalid style' do
+      expect(FastlaneCore::UI).to receive(:user_error!).with('Invalid value `failure` for parameter `style`. Valid values are: success, info, warning, error')
+
+      run_described_fastlane_action(
+        context: 'ctx',
+        style: 'failure',
+        message: 'Fake message'
+      )
+    end
+
+    %w[success info warning error].each do |style|
+      it "accepts `#{style}` as a valid style" do
+        expect(FastlaneCore::UI).not_to receive(:user_error!)
+        cmd = run_described_fastlane_action(
+          context: 'ctx',
+          style: style,
+          message: 'message'
+        )
+        expect(cmd).to eq("buildkite-agent annotate --context ctx --style #{style} message")
+      end
+    end
+
+    it 'accepts `nil` as a valid style' do
+      expect(FastlaneCore::UI).not_to receive(:user_error!)
+      cmd = run_described_fastlane_action(
+        context: 'ctx',
+        message: 'message'
+      )
+      expect(cmd).to eq('buildkite-agent annotate --context ctx message')
+    end
+  end
+
+  describe 'annotation creation' do
+    it 'generates the right command to create an annotation when message is provided' do
+      cmd = run_described_fastlane_action(
+        context: 'ctx',
+        style: 'warning',
+        message: 'message'
+      )
+      expect(cmd).to eq('buildkite-agent annotate --context ctx --style warning message')
+    end
+
+    it 'properly escapes the message and context' do
+      cmd = run_described_fastlane_action(
+        context: 'some ctx',
+        style: 'warning',
+        message: 'a <b>nice</b> message; with fun characters & all…'
+      )
+      expect(cmd).to eq('buildkite-agent annotate --context some\ ctx --style warning a\ \<b\>nice\</b\>\ message\;\ with\ fun\ characters\ \&\ all\…')
+    end
+
+    it 'falls back to Buildkite\'s default `context` when none is provided' do
+      cmd = run_described_fastlane_action(
+        style: 'warning',
+        message: 'a nice message'
+      )
+      expect(cmd).to eq('buildkite-agent annotate --style warning a\ nice\ message')
+    end
+
+    it 'falls back to Buildkite\'s default `style` when none is provided' do
+      cmd = run_described_fastlane_action(
+        context: 'my-ctx',
+        message: 'a nice message'
+      )
+      expect(cmd).to eq('buildkite-agent annotate --context my-ctx a\ nice\ message')
+    end
+  end
+
+  describe 'annotation deletion' do
+    it 'generates the right command to delete an annotation when no message is provided' do
+      cmd = run_described_fastlane_action(
+        context: 'some ctx',
+        message: nil
+      )
+      expect(cmd).to eq('buildkite-agent annotation remove --context some\ ctx || true')
+    end
+  end
+end
diff --git a/spec/buildkite_metadata_action_spec.rb b/spec/buildkite_metadata_action_spec.rb
new file mode 100644
index 000000000..867acdea4
--- /dev/null
+++ b/spec/buildkite_metadata_action_spec.rb
@@ -0,0 +1,45 @@
+require 'spec_helper'
+
+describe Fastlane::Actions::BuildkiteMetadataAction do
+  it 'calls the right command to set a single metadata' do
+    expect(Fastlane::Action).to receive(:sh).with('buildkite-agent', 'meta-data', 'set', 'foo', 'bar')
+
+    res = run_described_fastlane_action(set: { foo: 'bar' })
+    expect(res).to be_nil
+  end
+
+  it 'calls the commands as many times as necessary when we want to set multiple metadata at once' do
+    expect(Fastlane::Action).to receive(:sh).with('buildkite-agent', 'meta-data', 'set', 'key1', 'value1')
+    expect(Fastlane::Action).to receive(:sh).with('buildkite-agent', 'meta-data', 'set', 'key2', 'value2')
+
+    metadata = {
+      key1: 'value1',
+      key2: 'value2'
+    }
+    run_described_fastlane_action(set: metadata)
+  end
+
+  it 'calls the right command to get the value of metadata, and returns the right value' do
+    expect(Fastlane::Action).to receive(:sh).with('buildkite-agent', 'meta-data', 'get', 'foo')
+    allow(Fastlane::Action).to receive(:sh).with('buildkite-agent', 'meta-data', 'get', 'foo').and_return('foo value')
+
+    res = run_described_fastlane_action(get: 'foo')
+    expect(res).to eq('foo value')
+  end
+
+  it 'allows both setting and getting metadata in the same call' do
+    # Might not be the main way we intend to use this action… but it's still supported.
+    expect(Fastlane::Action).to receive(:sh).with('buildkite-agent', 'meta-data', 'set', 'key1', 'value1')
+    expect(Fastlane::Action).to receive(:sh).with('buildkite-agent', 'meta-data', 'set', 'key2', 'value2')
+    expect(Fastlane::Action).to receive(:sh).with('buildkite-agent', 'meta-data', 'get', 'key3')
+    allow(Fastlane::Action).to receive(:sh).with('buildkite-agent', 'meta-data', 'get', 'key3').and_return('value3')
+
+    new_metadata = {
+      key1: 'value1',
+      key2: 'value2'
+    }
+    res = run_described_fastlane_action(set: new_metadata, get: 'key3')
+
+    expect(res).to eq('value3')
+  end
+end