diff --git a/SPMS.API/appsettings.json b/SPMS.API/appsettings.json
index d5a32b5..185232c 100644
--- a/SPMS.API/appsettings.json
+++ b/SPMS.API/appsettings.json
@@ -22,6 +22,11 @@
     "PrefetchCount": 10,
     "MessageTtl": 86400000
   },
+  "Redis": {
+    "ConnectionString": "",
+    "InstanceName": "spms_dev_",
+    "DuplicateTtlHours": 24
+  },
   "CredentialEncryption": {
     "Key": ""
   },
diff --git a/SPMS.Application/Interfaces/IDuplicateChecker.cs b/SPMS.Application/Interfaces/IDuplicateChecker.cs
new file mode 100644
index 0000000..b4ede06
--- /dev/null
+++ b/SPMS.Application/Interfaces/IDuplicateChecker.cs
@@ -0,0 +1,6 @@
+namespace SPMS.Application.Interfaces;
+
+public interface IDuplicateChecker
+{
+    Task<bool> IsDuplicateAsync(string requestId, CancellationToken cancellationToken = default);
+}
diff --git a/SPMS.Application/Settings/RedisSettings.cs b/SPMS.Application/Settings/RedisSettings.cs
new file mode 100644
index 0000000..4fa2f42
--- /dev/null
+++ b/SPMS.Application/Settings/RedisSettings.cs
@@ -0,0 +1,10 @@
+namespace SPMS.Application.Settings;
+
+public class RedisSettings
+{
+    public const string SectionName = "Redis";
+
+    public string ConnectionString { get; set; } = "localhost:6379";
+    public string InstanceName { get; set; } = "spms_dev_";
+    public int DuplicateTtlHours { get; set; } = 24;
+}
diff --git a/SPMS.Infrastructure/Caching/DuplicateChecker.cs b/SPMS.Infrastructure/Caching/DuplicateChecker.cs
new file mode 100644
index 0000000..a256413
--- /dev/null
+++ b/SPMS.Infrastructure/Caching/DuplicateChecker.cs
@@ -0,0 +1,49 @@
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
+using SPMS.Application.Interfaces;
+using SPMS.Application.Settings;
+using StackExchange.Redis;
+
+namespace SPMS.Infrastructure.Caching;
+
+public class DuplicateChecker : IDuplicateChecker
+{
+    private readonly RedisConnection _redis;
+    private readonly RedisSettings _settings;
+    private readonly ILogger<DuplicateChecker> _logger;
+
+    public DuplicateChecker(
+        RedisConnection redis,
+        IOptions<RedisSettings> settings,
+        ILogger<DuplicateChecker> logger)
+    {
+        _redis = redis;
+        _settings = settings.Value;
+        _logger = logger;
+    }
+
+    public async Task<bool> IsDuplicateAsync(string requestId, CancellationToken cancellationToken = default)
+    {
+        var key = $"{_settings.InstanceName}duplicate:{requestId}";
+        var ttl = TimeSpan.FromHours(_settings.DuplicateTtlHours);
+
+        try
+        {
+            var db = await _redis.GetDatabaseAsync();
+            var wasSet = await db.StringSetAsync(key, "1", ttl, When.NotExists);
+
+            if (!wasSet)
+            {
+                _logger.LogWarning("중복 메시지 감지: requestId={RequestId}", requestId);
+                return true;
+            }
+
+            return false;
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "Redis 중복 체크 실패: requestId={RequestId} — 중복 아닌 것으로 처리", requestId);
+            return false;
+        }
+    }
+}
diff --git a/SPMS.Infrastructure/Caching/RedisConnection.cs b/SPMS.Infrastructure/Caching/RedisConnection.cs
new file mode 100644
index 0000000..2ac0f23
--- /dev/null
+++ b/SPMS.Infrastructure/Caching/RedisConnection.cs
@@ -0,0 +1,70 @@
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
+using SPMS.Application.Settings;
+using StackExchange.Redis;
+
+namespace SPMS.Infrastructure.Caching;
+
+public class RedisConnection : IAsyncDisposable
+{
+    private readonly RedisSettings _settings;
+    private readonly ILogger<RedisConnection> _logger;
+    private readonly SemaphoreSlim _semaphore = new(1, 1);
+    private ConnectionMultiplexer? _connection;
+
+    public RedisConnection(IOptions<RedisSettings> settings, ILogger<RedisConnection> logger)
+    {
+        _settings = settings.Value;
+        _logger = logger;
+    }
+
+    public async Task<IDatabase> GetDatabaseAsync()
+    {
+        if (_connection is { IsConnected: true })
+            return _connection.GetDatabase();
+
+        await _semaphore.WaitAsync();
+        try
+        {
+            if (_connection is { IsConnected: true })
+                return _connection.GetDatabase();
+
+            _connection?.Dispose();
+
+            _logger.LogInformation("Redis 연결 시도: {ConnectionString}",
+                MaskConnectionString(_settings.ConnectionString));
+
+            _connection = await ConnectionMultiplexer.ConnectAsync(_settings.ConnectionString);
+
+            _logger.LogInformation("Redis 연결 성공");
+            return _connection.GetDatabase();
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "Redis 연결 실패");
+            throw;
+        }
+        finally
+        {
+            _semaphore.Release();
+        }
+    }
+
+    private static string MaskConnectionString(string connectionString)
+    {
+        var parts = connectionString.Split(',');
+        return parts.Length > 0 ? parts[0] + ",..." : connectionString;
+    }
+
+    public async ValueTask DisposeAsync()
+    {
+        if (_connection != null)
+        {
+            await _connection.CloseAsync();
+            _connection.Dispose();
+        }
+
+        _semaphore.Dispose();
+        GC.SuppressFinalize(this);
+    }
+}
diff --git a/SPMS.Infrastructure/DependencyInjection.cs b/SPMS.Infrastructure/DependencyInjection.cs
index f455816..0eee960 100644
--- a/SPMS.Infrastructure/DependencyInjection.cs
+++ b/SPMS.Infrastructure/DependencyInjection.cs
@@ -5,6 +5,7 @@ using SPMS.Application.Interfaces;
 using SPMS.Application.Settings;
 using SPMS.Domain.Interfaces;
 using SPMS.Infrastructure.Auth;
+using SPMS.Infrastructure.Caching;
 using SPMS.Infrastructure.Messaging;
 using SPMS.Infrastructure.Persistence;
 using SPMS.Infrastructure.Push;
@@ -46,6 +47,11 @@ public static class DependencyInjection
         // File Storage
         services.AddSingleton<IFileStorageService, LocalFileStorageService>();
 
+        // Redis
+        services.Configure<RedisSettings>(configuration.GetSection(RedisSettings.SectionName));
+        services.AddSingleton<RedisConnection>();
+        services.AddSingleton<IDuplicateChecker, DuplicateChecker>();
+
         // RabbitMQ
         services.Configure<RabbitMQSettings>(configuration.GetSection(RabbitMQSettings.SectionName));
         services.AddSingleton<RabbitMQConnection>();
diff --git a/SPMS.Infrastructure/SPMS.Infrastructure.csproj b/SPMS.Infrastructure/SPMS.Infrastructure.csproj
index 7a25b55..a8404cf 100644
--- a/SPMS.Infrastructure/SPMS.Infrastructure.csproj
+++ b/SPMS.Infrastructure/SPMS.Infrastructure.csproj
@@ -21,6 +21,7 @@
       <PackageReference Include="Microsoft.Extensions.Options.ConfigurationExtensions" Version="10.0.2" />
       <PackageReference Include="Pomelo.EntityFrameworkCore.MySql" Version="9.0.0" />
       <PackageReference Include="RabbitMQ.Client" Version="7.2.0" />
+      <PackageReference Include="StackExchange.Redis" Version="2.10.14" />
       <PackageReference Include="System.IdentityModel.Tokens.Jwt" Version="8.15.0" />
     </ItemGroup>