diff --git a/MoneyMap/Pages/Receipts.cshtml b/MoneyMap/Pages/Receipts.cshtml
index f4bc2e3..7fd5fef 100644
--- a/MoneyMap/Pages/Receipts.cshtml
+++ b/MoneyMap/Pages/Receipts.cshtml
@@ -73,9 +73,19 @@
 
 <!-- Receipts List -->
 <div class="card shadow-sm">
-    <div class="card-header">
-        <strong>All Receipts</strong>
-        <span class="text-muted">- @Model.Receipts.Count total</span>
+    <div class="card-header d-flex justify-content-between align-items-center">
+        <div>
+            <strong>All Receipts</strong>
+            <span class="text-muted">- @Model.Receipts.Count total</span>
+        </div>
+        @if (Model.Receipts.Any(r => !r.TransactionId.HasValue && (!string.IsNullOrWhiteSpace(r.Merchant) || r.ReceiptDate.HasValue || r.Total.HasValue)))
+        {
+            <form method="post" asp-page-handler="AutoMapUnmapped" style="display: inline;">
+                <button type="submit" class="btn btn-sm btn-success" title="Automatically map unmapped receipts to matching transactions">
+                    🔗 Auto-Map Unmapped Receipts
+                </button>
+            </form>
+        }
     </div>
     <div class="card-body p-0">
         @if (Model.Receipts.Any())
diff --git a/MoneyMap/Pages/Receipts.cshtml.cs b/MoneyMap/Pages/Receipts.cshtml.cs
index b634a6b..06d5bab 100644
--- a/MoneyMap/Pages/Receipts.cshtml.cs
+++ b/MoneyMap/Pages/Receipts.cshtml.cs
@@ -11,11 +11,13 @@ namespace MoneyMap.Pages
     {
         private readonly MoneyMapContext _db;
         private readonly IReceiptManager _receiptManager;
+        private readonly IReceiptAutoMapper _autoMapper;
 
-        public ReceiptsModel(MoneyMapContext db, IReceiptManager receiptManager)
+        public ReceiptsModel(MoneyMapContext db, IReceiptManager receiptManager, IReceiptAutoMapper autoMapper)
         {
             _db = db;
             _receiptManager = receiptManager;
+            _autoMapper = autoMapper;
         }
 
         public List<ReceiptRow> Receipts { get; set; } = new();
@@ -117,6 +119,32 @@ namespace MoneyMap.Pages
             return RedirectToPage();
         }
 
+        public async Task<IActionResult> OnPostAutoMapUnmappedAsync()
+        {
+            var result = await _autoMapper.AutoMapUnmappedReceiptsAsync();
+
+            if (result.MappedCount > 0)
+            {
+                Message = $"Successfully auto-mapped {result.MappedCount} receipt(s). " +
+                         $"{result.NoMatchCount} had no matching transaction. " +
+                         $"{result.MultipleMatchesCount} had multiple potential matches.";
+                IsSuccess = true;
+            }
+            else if (result.TotalProcessed == 0)
+            {
+                Message = "No unmapped parsed receipts found to process.";
+                IsSuccess = false;
+            }
+            else
+            {
+                Message = $"Unable to auto-map any receipts. {result.NoMatchCount} had no matching transaction. " +
+                         $"{result.MultipleMatchesCount} had multiple potential matches.";
+                IsSuccess = false;
+            }
+
+            return RedirectToPage();
+        }
+
         private async Task LoadReceiptsAsync()
         {
             var receipts = await _db.Receipts
diff --git a/MoneyMap/Program.cs b/MoneyMap/Program.cs
index c2802d1..54c9b80 100644
--- a/MoneyMap/Program.cs
+++ b/MoneyMap/Program.cs
@@ -32,6 +32,7 @@ builder.Services.AddScoped<IDashboardStatsCalculator, DashboardStatsCalculator>(
 builder.Services.AddScoped<ITopCategoriesProvider, TopCategoriesProvider>();
 builder.Services.AddScoped<IRecentTransactionsProvider, RecentTransactionsProvider>();
 builder.Services.AddScoped<IReceiptManager, ReceiptManager>();
+builder.Services.AddScoped<IReceiptAutoMapper, ReceiptAutoMapper>();
 builder.Services.AddHttpClient<IReceiptParser, OpenAIReceiptParser>();
 
 // AI categorization service
diff --git a/MoneyMap/Services/OpenAIReceiptParser.cs b/MoneyMap/Services/OpenAIReceiptParser.cs
index 9bd345f..50d09e6 100644
--- a/MoneyMap/Services/OpenAIReceiptParser.cs
+++ b/MoneyMap/Services/OpenAIReceiptParser.cs
@@ -27,19 +27,22 @@ namespace MoneyMap.Services
         private readonly IConfiguration _configuration;
         private readonly HttpClient _httpClient;
         private readonly IMerchantService _merchantService;
+        private readonly IServiceProvider _serviceProvider;
 
         public OpenAIReceiptParser(
             MoneyMapContext db,
             IWebHostEnvironment environment,
             IConfiguration configuration,
             HttpClient httpClient,
-            IMerchantService merchantService)
+            IMerchantService merchantService,
+            IServiceProvider serviceProvider)
         {
             _db = db;
             _environment = environment;
             _configuration = configuration;
             _httpClient = httpClient;
             _merchantService = merchantService;
+            _serviceProvider = serviceProvider;
         }
 
         public async Task<ReceiptParseResult> ParseReceiptAsync(long receiptId)
@@ -138,6 +141,22 @@ namespace MoneyMap.Services
                 _db.ReceiptParseLogs.Add(parseLog);
                 await _db.SaveChangesAsync();
 
+                // Attempt auto-mapping after successful parse (only if receipt is not already mapped)
+                if (!receipt.TransactionId.HasValue)
+                {
+                    try
+                    {
+                        // Use service locator pattern to avoid circular dependency
+                        using var scope = _serviceProvider.CreateScope();
+                        var autoMapper = scope.ServiceProvider.GetRequiredService<IReceiptAutoMapper>();
+                        await autoMapper.AutoMapReceiptAsync(receiptId);
+                    }
+                    catch
+                    {
+                        // Ignore auto-mapping errors - parsing was successful
+                    }
+                }
+
                 return ReceiptParseResult.Success($"Parsed {lineItems.Count} line items from receipt.");
             }
             catch (Exception ex)
diff --git a/MoneyMap/Services/ReceiptAutoMapper.cs b/MoneyMap/Services/ReceiptAutoMapper.cs
new file mode 100644
index 0000000..5d49c9b
--- /dev/null
+++ b/MoneyMap/Services/ReceiptAutoMapper.cs
@@ -0,0 +1,194 @@
+using Microsoft.EntityFrameworkCore;
+using MoneyMap.Data;
+using MoneyMap.Models;
+
+namespace MoneyMap.Services
+{
+    public interface IReceiptAutoMapper
+    {
+        Task<ReceiptAutoMapResult> AutoMapReceiptAsync(long receiptId);
+        Task<BulkAutoMapResult> AutoMapUnmappedReceiptsAsync();
+    }
+
+    public class ReceiptAutoMapper : IReceiptAutoMapper
+    {
+        private readonly MoneyMapContext _db;
+        private readonly IReceiptManager _receiptManager;
+
+        public ReceiptAutoMapper(MoneyMapContext db, IReceiptManager receiptManager)
+        {
+            _db = db;
+            _receiptManager = receiptManager;
+        }
+
+        public async Task<ReceiptAutoMapResult> AutoMapReceiptAsync(long receiptId)
+        {
+            var receipt = await _db.Receipts
+                .Include(r => r.Transaction)
+                .FirstOrDefaultAsync(r => r.Id == receiptId);
+
+            if (receipt == null)
+                return ReceiptAutoMapResult.Failure("Receipt not found.");
+
+            // If already mapped, skip
+            if (receipt.TransactionId.HasValue)
+                return ReceiptAutoMapResult.AlreadyMapped(receipt.TransactionId.Value);
+
+            // If receipt has not been parsed (no merchant, date, or total), skip
+            if (string.IsNullOrWhiteSpace(receipt.Merchant) && !receipt.ReceiptDate.HasValue && !receipt.Total.HasValue)
+                return ReceiptAutoMapResult.NotParsed();
+
+            // Find matching transactions based on parsed data
+            var candidateTransactions = await FindMatchingTransactionsAsync(receipt);
+
+            if (candidateTransactions.Count == 0)
+                return ReceiptAutoMapResult.NoMatch();
+
+            if (candidateTransactions.Count > 1)
+                return ReceiptAutoMapResult.MultipleMatches(candidateTransactions);
+
+            // Single match found - auto-map it
+            var transaction = candidateTransactions[0];
+            var success = await _receiptManager.MapReceiptToTransactionAsync(receiptId, transaction.Id);
+
+            if (success)
+                return ReceiptAutoMapResult.Success(transaction.Id);
+            else
+                return ReceiptAutoMapResult.Failure("Failed to map receipt to transaction.");
+        }
+
+        public async Task<BulkAutoMapResult> AutoMapUnmappedReceiptsAsync()
+        {
+            var unmappedReceipts = await _db.Receipts
+                .Where(r => r.TransactionId == null)
+                .Where(r => r.Merchant != null || r.ReceiptDate != null || r.Total != null) // Only parsed receipts
+                .ToListAsync();
+
+            var result = new BulkAutoMapResult();
+
+            foreach (var receipt in unmappedReceipts)
+            {
+                var mapResult = await AutoMapReceiptAsync(receipt.Id);
+
+                if (mapResult.Status == AutoMapStatus.Success)
+                {
+                    result.MappedCount++;
+                }
+                else if (mapResult.Status == AutoMapStatus.MultipleMatches)
+                {
+                    result.MultipleMatchesCount++;
+                }
+                else if (mapResult.Status == AutoMapStatus.NoMatch)
+                {
+                    result.NoMatchCount++;
+                }
+            }
+
+            result.TotalProcessed = unmappedReceipts.Count;
+            return result;
+        }
+
+        private async Task<List<Transaction>> FindMatchingTransactionsAsync(Receipt receipt)
+        {
+            var query = _db.Transactions
+                .Include(t => t.Card)
+                .Include(t => t.Account)
+                .Include(t => t.Merchant)
+                .AsQueryable();
+
+            // Start with date range filter (if we have a receipt date)
+            if (receipt.ReceiptDate.HasValue)
+            {
+                // Allow +/- 3 days for transaction date to account for processing delays
+                var minDate = receipt.ReceiptDate.Value.AddDays(-3);
+                var maxDate = receipt.ReceiptDate.Value.AddDays(3);
+                query = query.Where(t => t.Date >= minDate && t.Date <= maxDate);
+            }
+            else
+            {
+                // If no receipt date, can't narrow down effectively
+                return new List<Transaction>();
+            }
+
+            // Filter by merchant if available
+            if (!string.IsNullOrWhiteSpace(receipt.Merchant))
+            {
+                // Try to find matching merchant name
+                query = query.Where(t =>
+                    (t.Merchant != null && t.Merchant.Name.Contains(receipt.Merchant)) ||
+                    t.Name.Contains(receipt.Merchant));
+            }
+
+            // Get candidates
+            var candidates = await query.ToListAsync();
+
+            // If we have a total amount, filter by amount match
+            if (receipt.Total.HasValue)
+            {
+                // Allow for slight variations in amount (e.g., due to rounding)
+                // Match if transaction amount is within $0.10 of receipt total
+                var receiptTotal = Math.Abs(receipt.Total.Value);
+                candidates = candidates
+                    .Where(t => Math.Abs(Math.Abs(t.Amount) - receiptTotal) <= 0.10m)
+                    .ToList();
+            }
+
+            // Exclude transactions that already have receipts
+            var transactionsWithReceipts = await _db.Receipts
+                .Where(r => r.TransactionId != null)
+                .Select(r => r.TransactionId!.Value)
+                .Distinct()
+                .ToListAsync();
+
+            candidates = candidates
+                .Where(t => !transactionsWithReceipts.Contains(t.Id))
+                .ToList();
+
+            return candidates;
+        }
+    }
+
+    public class ReceiptAutoMapResult
+    {
+        public AutoMapStatus Status { get; init; }
+        public long? TransactionId { get; init; }
+        public List<Transaction> MultipleMatches { get; init; } = new();
+        public string? Message { get; init; }
+
+        public static ReceiptAutoMapResult Success(long transactionId) =>
+            new() { Status = AutoMapStatus.Success, TransactionId = transactionId };
+
+        public static ReceiptAutoMapResult AlreadyMapped(long transactionId) =>
+            new() { Status = AutoMapStatus.AlreadyMapped, TransactionId = transactionId };
+
+        public static ReceiptAutoMapResult NoMatch() =>
+            new() { Status = AutoMapStatus.NoMatch, Message = "No matching transaction found." };
+
+        public static ReceiptAutoMapResult MultipleMatches(List<Transaction> matches) =>
+            new() { Status = AutoMapStatus.MultipleMatches, MultipleMatches = matches, Message = $"Found {matches.Count} potential matches." };
+
+        public static ReceiptAutoMapResult NotParsed() =>
+            new() { Status = AutoMapStatus.NotParsed, Message = "Receipt has not been parsed yet." };
+
+        public static ReceiptAutoMapResult Failure(string message) =>
+            new() { Status = AutoMapStatus.Failed, Message = message };
+    }
+
+    public class BulkAutoMapResult
+    {
+        public int TotalProcessed { get; set; }
+        public int MappedCount { get; set; }
+        public int NoMatchCount { get; set; }
+        public int MultipleMatchesCount { get; set; }
+    }
+
+    public enum AutoMapStatus
+    {
+        Success,
+        AlreadyMapped,
+        NoMatch,
+        MultipleMatches,
+        NotParsed,
+        Failed
+    }
+}