diff --git a/Jellyfin.Server/Migrations/Routines/MigrateLibraryDb.cs b/Jellyfin.Server/Migrations/Routines/MigrateLibraryDb.cs
index 7bb379eb68..e25c52786b 100644
--- a/Jellyfin.Server/Migrations/Routines/MigrateLibraryDb.cs
+++ b/Jellyfin.Server/Migrations/Routines/MigrateLibraryDb.cs
@@ -183,12 +183,12 @@ internal class MigrateLibraryDb : IDatabaseMigrationRoutine
 
             using (new TrackedMigrationStep("Loading UserData", _logger))
             {
-                var users = operation.JellyfinDbContext.Users.AsNoTracking().ToImmutableArray();
+                var users = operation.JellyfinDbContext.Users.AsNoTracking().ToArray();
                 var userIdBlacklist = new HashSet<int>();
 
                 foreach (var entity in queryResult)
                 {
-                    var userData = GetUserData(users, entity, userIdBlacklist);
+                    var userData = GetUserData(users, entity, userIdBlacklist, _logger);
                     if (userData is null)
                     {
                         var userDataId = entity.GetString(0);
@@ -212,8 +212,6 @@ internal class MigrateLibraryDb : IDatabaseMigrationRoutine
                     userData.ItemId = refItem.Id;
                     operation.JellyfinDbContext.UserData.Add(userData);
                 }
-
-                users.Clear();
             }
 
             legacyBaseItemWithUserKeys.Clear();
@@ -404,7 +402,7 @@ internal class MigrateLibraryDb : IDatabaseMigrationRoutine
         return new DatabaseMigrationStep(dbContext, operationName, _logger);
     }
 
-    private UserData? GetUserData(ImmutableArray<User> users, SqliteDataReader dto, HashSet<int> userIdBlacklist)
+    internal static UserData? GetUserData(User[] users, SqliteDataReader dto, HashSet<int> userIdBlacklist, ILogger logger)
     {
         var internalUserId = dto.GetInt32(1);
         if (userIdBlacklist.Contains(internalUserId))
@@ -415,9 +413,9 @@ internal class MigrateLibraryDb : IDatabaseMigrationRoutine
         var user = users.FirstOrDefault(e => e.InternalId == internalUserId);
         if (user is null)
         {
-            _logger.LogError("Tried to find user with index '{Idx}' but was not found, skipping user data import.", internalUserId);
             userIdBlacklist.Add(internalUserId);
 
+            logger.LogError("Tried to find user with index '{Idx}' but there are only '{MaxIdx}' users.", internalUserId, users.Length);
             return null;
         }
 
diff --git a/Jellyfin.Server/Migrations/Routines/MigrateLibraryUserData.cs b/Jellyfin.Server/Migrations/Routines/MigrateLibraryUserData.cs
new file mode 100644
index 0000000000..beb8c0a9bd
--- /dev/null
+++ b/Jellyfin.Server/Migrations/Routines/MigrateLibraryUserData.cs
@@ -0,0 +1,107 @@
+#pragma warning disable RS0030 // Do not use banned APIs
+
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using Emby.Server.Implementations.Data;
+using Jellyfin.Database.Implementations;
+using Jellyfin.Server.Implementations.Item;
+using Jellyfin.Server.ServerSetupApp;
+using MediaBrowser.Controller;
+using Microsoft.Data.Sqlite;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Logging;
+
+namespace Jellyfin.Server.Migrations.Routines;
+
+[JellyfinMigration("2025-06-18T01:00:00", nameof(MigrateLibraryUserData))]
+[JellyfinMigrationBackup(JellyfinDb = true)]
+internal class MigrateLibraryUserData : IAsyncMigrationRoutine
+{
+    private const string DbFilename = "library.db.old";
+
+    private readonly IStartupLogger _logger;
+    private readonly IServerApplicationPaths _paths;
+    private readonly IDbContextFactory<JellyfinDbContext> _provider;
+
+    public MigrateLibraryUserData(
+            IStartupLogger<MigrateLibraryDb> startupLogger,
+            IDbContextFactory<JellyfinDbContext> provider,
+            IServerApplicationPaths paths)
+    {
+        _logger = startupLogger;
+        _provider = provider;
+        _paths = paths;
+    }
+
+    public async Task PerformAsync(CancellationToken cancellationToken)
+    {
+        _logger.LogInformation("Migrating the userdata from library.db.old may take a while, do not stop Jellyfin.");
+
+        var dataPath = _paths.DataPath;
+        var libraryDbPath = Path.Combine(dataPath, DbFilename);
+        if (!File.Exists(libraryDbPath))
+        {
+            _logger.LogError("Cannot migrate userdata from {LibraryDb} as it does not exist. This migration expects the MigrateLibraryDb to run first.", libraryDbPath);
+            return;
+        }
+
+        var dbContext = await _provider.CreateDbContextAsync(cancellationToken).ConfigureAwait(false);
+        await using (dbContext.ConfigureAwait(false))
+        {
+            if (!await dbContext.BaseItems.AnyAsync(e => e.Id == BaseItemRepository.PlaceholderId, cancellationToken).ConfigureAwait(false))
+            {
+                // the placeholder baseitem has been deleted by the librarydb migration so we need to readd it.
+                await dbContext.BaseItems.AddAsync(
+                    new Database.Implementations.Entities.BaseItemEntity()
+                    {
+                        Id = BaseItemRepository.PlaceholderId,
+                        Type = "PLACEHOLDER",
+                        Name = "This is a placeholder item for UserData that has been detacted from its original item"
+                    },
+                    cancellationToken)
+                    .ConfigureAwait(false);
+                await dbContext.SaveChangesAsync(cancellationToken).ConfigureAwait(false);
+            }
+
+            var users = dbContext.Users.AsNoTracking().ToArray();
+            var userIdBlacklist = new HashSet<int>();
+            using var connection = new SqliteConnection($"Filename={libraryDbPath};Mode=ReadOnly");
+            var retentionDate = DateTime.UtcNow;
+
+            var queryResult = connection.Query(
+"""
+    SELECT key, userId, rating, played, playCount, isFavorite, playbackPositionTicks, lastPlayedDate, AudioStreamIndex, SubtitleStreamIndex FROM UserDatas
+
+    WHERE NOT EXISTS(SELECT 1 FROM TypedBaseItems WHERE TypedBaseItems.UserDataKey = UserDatas.key)
+""");
+            foreach (var entity in queryResult)
+            {
+                var userData = MigrateLibraryDb.GetUserData(users, entity, userIdBlacklist, _logger);
+                if (userData is null)
+                {
+                    var userDataId = entity.GetString(0);
+                    var internalUserId = entity.GetInt32(1);
+
+                    if (!userIdBlacklist.Contains(internalUserId))
+                    {
+                        _logger.LogError("Was not able to migrate user data with key {0} because its id {InternalId} does not match any existing user.", userDataId, internalUserId);
+                        userIdBlacklist.Add(internalUserId);
+                    }
+
+                    continue;
+                }
+
+                userData.ItemId = BaseItemRepository.PlaceholderId;
+                userData.RetentionDate = retentionDate;
+                dbContext.UserData.Add(userData);
+            }
+
+            _logger.LogInformation("Try saving {NewSaved} UserData entries.", dbContext.UserData.Local.Count);
+            await dbContext.SaveChangesAsync(cancellationToken).ConfigureAwait(false);
+        }
+    }
+}