diff --git a/SabreTools.Serialization.Test/Deserializers/AppPkgHeaderTests.cs b/SabreTools.Serialization.Test/Deserializers/AppPkgHeaderTests.cs
new file mode 100644
index 00000000..e6b7cc48
--- /dev/null
+++ b/SabreTools.Serialization.Test/Deserializers/AppPkgHeaderTests.cs
@@ -0,0 +1,73 @@
+using System.IO;
+using System.Linq;
+using SabreTools.Serialization.Deserializers;
+using Xunit;
+
+namespace SabreTools.Serialization.Test.Deserializers
+{
+    public class AppPkgHeaderTests
+    {
+        [Fact]
+        public void NullArray_Null()
+        {
+            byte[]? data = null;
+            int offset = 0;
+            var deserializer = new AppPkgHeader();
+
+            var actual = deserializer.Deserialize(data, offset);
+            Assert.Null(actual);
+        }
+
+        [Fact]
+        public void EmptyArray_Null()
+        {
+            byte[]? data = [];
+            int offset = 0;
+            var deserializer = new AppPkgHeader();
+
+            var actual = deserializer.Deserialize(data, offset);
+            Assert.Null(actual);
+        }
+
+        [Fact]
+        public void InvalidArray_Null()
+        {
+            byte[]? data = [.. Enumerable.Repeat<byte>(0xFF, 1024)];
+            int offset = 0;
+            var deserializer = new AppPkgHeader();
+
+            var actual = deserializer.Deserialize(data, offset);
+            Assert.Null(actual);
+        }
+
+        [Fact]
+        public void NullStream_Null()
+        {
+            Stream? data = null;
+            var deserializer = new AppPkgHeader();
+
+            var actual = deserializer.Deserialize(data);
+            Assert.Null(actual);
+        }
+
+        [Fact]
+        public void EmptyStream_Null()
+        {
+            Stream? data = new MemoryStream([]);
+            var deserializer = new AppPkgHeader();
+
+            var actual = deserializer.Deserialize(data);
+            Assert.Null(actual);
+        }
+
+        [Fact]
+        public void InvalidStream_Null()
+        {
+            Stream? data = new MemoryStream([.. Enumerable.Repeat<byte>(0xFF, 1024)]);
+            var deserializer = new AppPkgHeader();
+
+            var actual = deserializer.Deserialize(data);
+            Assert.Null(actual);
+        }
+    }
+}
\ No newline at end of file
diff --git a/SabreTools.Serialization/Deserializers/AppPkgHeader.cs b/SabreTools.Serialization/Deserializers/AppPkgHeader.cs
new file mode 100644
index 00000000..2b9f6da3
--- /dev/null
+++ b/SabreTools.Serialization/Deserializers/AppPkgHeader.cs
@@ -0,0 +1,79 @@
+using System.IO;
+using System.Text;
+using SabreTools.IO.Extensions;
+using static SabreTools.Models.PlayStation4.Constants;
+
+namespace SabreTools.Serialization.Deserializers
+{
+    public class AppPkgHeader : BaseBinaryDeserializer<Models.PlayStation4.AppPkgHeader>
+    {
+        /// <inheritdoc/>
+        public override Models.PlayStation4.AppPkgHeader? Deserialize(Stream? data)
+        {
+            // If the data is invalid
+            if (data == null || !data.CanRead)
+                return null;
+
+            try
+            {
+                // Create a new app.pkg header to fill
+                var appPkgHeader = new Models.PlayStation4.AppPkgHeader();
+
+                appPkgHeader.Magic = data.ReadUInt32BigEndian();
+                if (appPkgHeader.Magic != AppPkgMagic)
+                    return null;
+
+                appPkgHeader.Type = data.ReadUInt32BigEndian();
+                appPkgHeader.PKGUnknown = data.ReadUInt32BigEndian();
+                appPkgHeader.FileCount = data.ReadUInt32BigEndian();
+                appPkgHeader.EntryCount = data.ReadUInt32BigEndian();
+                appPkgHeader.SCEntryCount = data.ReadUInt16BigEndian();
+                appPkgHeader.EntryCount2 = data.ReadUInt16BigEndian();
+                appPkgHeader.TableOffset = data.ReadUInt32BigEndian();
+                appPkgHeader.EntryDataSize = data.ReadUInt32BigEndian();
+                appPkgHeader.BodyOffset = data.ReadUInt64BigEndian();
+                appPkgHeader.BodySize = data.ReadUInt64BigEndian();
+                appPkgHeader.ContentOffset = data.ReadUInt64BigEndian();
+                appPkgHeader.ContentSize = data.ReadUInt64BigEndian();
+                byte[] contentID = data.ReadBytes(0x24);
+                appPkgHeader.ContentID = Encoding.ASCII.GetString(contentID).TrimEnd('\0');
+                appPkgHeader.ContentZeroes = data.ReadBytes(0xC);
+                appPkgHeader.DRMType = data.ReadUInt32BigEndian();
+                appPkgHeader.ContentType = data.ReadUInt32BigEndian();
+                appPkgHeader.ContentFlags = data.ReadUInt32BigEndian();
+                appPkgHeader.PromoteSize = data.ReadUInt32BigEndian();
+                appPkgHeader.VersionDate = data.ReadUInt32BigEndian();
+                appPkgHeader.VersionHash = data.ReadUInt32BigEndian();
+                appPkgHeader.Zeroes1 = data.ReadBytes(0x78);
+                appPkgHeader.MainEntry1SHA256 = data.ReadBytes(0x20);
+                appPkgHeader.MainEntry2SHA256 = data.ReadBytes(0x20);
+                appPkgHeader.DigestTableSHA256 = data.ReadBytes(0x20);
+                appPkgHeader.MainTableSHA256 = data.ReadBytes(0x20);
+                appPkgHeader.Zeroes2 = data.ReadBytes(0x280);
+                appPkgHeader.PFSUnknown = data.ReadUInt32BigEndian();
+                appPkgHeader.PFSImageCount = data.ReadUInt32BigEndian();
+                appPkgHeader.PFSImageFlags = data.ReadUInt64BigEndian();
+                appPkgHeader.PFSImageOffset = data.ReadUInt64BigEndian();
+                appPkgHeader.PFSImageSize = data.ReadUInt64BigEndian();
+                appPkgHeader.MountImageOffset = data.ReadUInt64BigEndian();
+                appPkgHeader.MountImageSize = data.ReadUInt64BigEndian();
+                appPkgHeader.PKGSize = data.ReadUInt64BigEndian();
+                appPkgHeader.PKGSignedSize = data.ReadUInt32BigEndian();
+                appPkgHeader.PKGCacheSize = data.ReadUInt32BigEndian();
+                appPkgHeader.PFSImageSHA256 = data.ReadBytes(0x20);
+                appPkgHeader.PFSSignedSHA256 = data.ReadBytes(0x20);
+                appPkgHeader.PFSSplitSize0 = data.ReadUInt64BigEndian();
+                appPkgHeader.PFSSplitSize1 = data.ReadUInt64BigEndian();
+                appPkgHeader.Zeroes3 = data.ReadBytes(0xB50);
+                appPkgHeader.PKGSHA256 = data.ReadBytes(0x20);
+
+                return appPkgHeader;
+            }
+            catch
+            {
+                // Ignore the actual error
+                return null;
+            }
+        }
+    }
+}
\ No newline at end of file