diff --git a/SPMS.API/Controllers/PushController.cs b/SPMS.API/Controllers/PushController.cs
new file mode 100644
index 0000000..ba3e5e6
--- /dev/null
+++ b/SPMS.API/Controllers/PushController.cs
@@ -0,0 +1,46 @@
+using Microsoft.AspNetCore.Mvc;
+using Swashbuckle.AspNetCore.Annotations;
+using SPMS.Application.DTOs.Push;
+using SPMS.Application.Interfaces;
+using SPMS.Domain.Common;
+
+namespace SPMS.API.Controllers;
+
+[ApiController]
+[Route("v1/in/push")]
+[ApiExplorerSettings(GroupName = "push")]
+public class PushController : ControllerBase
+{
+    private readonly IPushService _pushService;
+
+    public PushController(IPushService pushService)
+    {
+        _pushService = pushService;
+    }
+
+    [HttpPost("send")]
+    [SwaggerOperation(Summary = "단건 발송", Description = "특정 디바이스에 푸시 메시지를 즉시 발송합니다.")]
+    public async Task<IActionResult> SendAsync([FromBody] PushSendRequestDto request)
+    {
+        var serviceId = GetServiceId();
+        var result = await _pushService.SendAsync(serviceId, request);
+        return Ok(ApiResponse<PushSendResponseDto>.Success(result));
+    }
+
+    [HttpPost("send/tag")]
+    [SwaggerOperation(Summary = "태그 발송", Description = "태그 조건에 해당하는 디바이스에 푸시 메시지를 발송합니다.")]
+    public async Task<IActionResult> SendByTagAsync([FromBody] PushSendTagRequestDto request)
+    {
+        var serviceId = GetServiceId();
+        var result = await _pushService.SendByTagAsync(serviceId, request);
+        return Ok(ApiResponse<PushSendResponseDto>.Success(result));
+    }
+
+    private long GetServiceId()
+    {
+        if (HttpContext.Items.TryGetValue("ServiceId", out var serviceIdObj) && serviceIdObj is long serviceId)
+            return serviceId;
+
+        throw new Domain.Exceptions.SpmsException(ErrorCodes.BadRequest, "서비스 식별 정보가 없습니다.", 400);
+    }
+}
diff --git a/SPMS.Application/DependencyInjection.cs b/SPMS.Application/DependencyInjection.cs
index 05675cb..5d01307 100644
--- a/SPMS.Application/DependencyInjection.cs
+++ b/SPMS.Application/DependencyInjection.cs
@@ -18,6 +18,7 @@ public static class DependencyInjection
         services.AddScoped<IAppConfigService, AppConfigService>();
         services.AddScoped<IDeviceService, DeviceService>();
         services.AddScoped<IFileService, FileService>();
+        services.AddScoped<IPushService, PushService>();
 
         return services;
     }
diff --git a/SPMS.Application/Interfaces/IPushService.cs b/SPMS.Application/Interfaces/IPushService.cs
new file mode 100644
index 0000000..b393220
--- /dev/null
+++ b/SPMS.Application/Interfaces/IPushService.cs
@@ -0,0 +1,9 @@
+using SPMS.Application.DTOs.Push;
+
+namespace SPMS.Application.Interfaces;
+
+public interface IPushService
+{
+    Task<PushSendResponseDto> SendAsync(long serviceId, PushSendRequestDto request);
+    Task<PushSendResponseDto> SendByTagAsync(long serviceId, PushSendTagRequestDto request);
+}
diff --git a/SPMS.Application/Services/PushService.cs b/SPMS.Application/Services/PushService.cs
new file mode 100644
index 0000000..200b364
--- /dev/null
+++ b/SPMS.Application/Services/PushService.cs
@@ -0,0 +1,124 @@
+using System.Text.Json;
+using SPMS.Application.DTOs.Push;
+using SPMS.Application.Interfaces;
+using SPMS.Domain.Common;
+using SPMS.Domain.Exceptions;
+using SPMS.Domain.Interfaces;
+
+namespace SPMS.Application.Services;
+
+public class PushService : IPushService
+{
+    private readonly IMessageRepository _messageRepository;
+    private readonly IPushQueueService _pushQueueService;
+
+    public PushService(IMessageRepository messageRepository, IPushQueueService pushQueueService)
+    {
+        _messageRepository = messageRepository;
+        _pushQueueService = pushQueueService;
+    }
+
+    public async Task<PushSendResponseDto> SendAsync(long serviceId, PushSendRequestDto request)
+    {
+        var message = await _messageRepository.GetByMessageCodeAndServiceAsync(request.MessageCode, serviceId);
+        if (message == null)
+            throw new SpmsException(ErrorCodes.MessageNotFound, "존재하지 않는 메시지 코드입니다.", 404);
+
+        var title = ApplyVariables(message.Title, request.Variables);
+        var body = ApplyVariables(message.Body, request.Variables);
+
+        var requestId = Guid.NewGuid().ToString("N");
+
+        var pushMessage = new PushMessageDto
+        {
+            MessageId = message.Id.ToString(),
+            RequestId = requestId,
+            ServiceId = serviceId,
+            SendType = "single",
+            Title = title,
+            Body = body,
+            ImageUrl = message.ImageUrl,
+            LinkUrl = message.LinkUrl,
+            CustomData = ParseCustomData(message.CustomData),
+            Target = new PushTargetDto
+            {
+                Type = "device_ids",
+                Value = JsonSerializer.SerializeToElement(new[] { request.DeviceId })
+            },
+            CreatedBy = message.CreatedBy,
+            CreatedAt = DateTime.UtcNow.ToString("o")
+        };
+
+        await _pushQueueService.PublishPushMessageAsync(pushMessage);
+
+        return new PushSendResponseDto
+        {
+            RequestId = requestId,
+            SendType = "single",
+            Status = "queued"
+        };
+    }
+
+    public async Task<PushSendResponseDto> SendByTagAsync(long serviceId, PushSendTagRequestDto request)
+    {
+        var message = await _messageRepository.GetByMessageCodeAndServiceAsync(request.MessageCode, serviceId);
+        if (message == null)
+            throw new SpmsException(ErrorCodes.MessageNotFound, "존재하지 않는 메시지 코드입니다.", 404);
+
+        var requestId = Guid.NewGuid().ToString("N");
+
+        var pushMessage = new PushMessageDto
+        {
+            MessageId = message.Id.ToString(),
+            RequestId = requestId,
+            ServiceId = serviceId,
+            SendType = "group",
+            Title = message.Title,
+            Body = message.Body,
+            ImageUrl = message.ImageUrl,
+            LinkUrl = message.LinkUrl,
+            CustomData = ParseCustomData(message.CustomData),
+            Target = new PushTargetDto
+            {
+                Type = "tags",
+                Value = JsonSerializer.SerializeToElement(new
+                {
+                    tags = request.Tags,
+                    match = request.TagMatch
+                })
+            },
+            CreatedBy = message.CreatedBy,
+            CreatedAt = DateTime.UtcNow.ToString("o")
+        };
+
+        await _pushQueueService.PublishPushMessageAsync(pushMessage);
+
+        return new PushSendResponseDto
+        {
+            RequestId = requestId,
+            SendType = "group",
+            Status = "queued"
+        };
+    }
+
+    private static string ApplyVariables(string template, Dictionary<string, string>? variables)
+    {
+        if (variables == null || variables.Count == 0)
+            return template;
+
+        var result = template;
+        foreach (var (key, value) in variables)
+        {
+            result = result.Replace($"{{{{{key}}}}}", value);
+        }
+        return result;
+    }
+
+    private static Dictionary<string, object>? ParseCustomData(string? customData)
+    {
+        if (string.IsNullOrWhiteSpace(customData))
+            return null;
+
+        return JsonSerializer.Deserialize<Dictionary<string, object>>(customData);
+    }
+}
diff --git a/SPMS.Domain/Common/ErrorCodes.cs b/SPMS.Domain/Common/ErrorCodes.cs
index 4b64796..552aa20 100644
--- a/SPMS.Domain/Common/ErrorCodes.cs
+++ b/SPMS.Domain/Common/ErrorCodes.cs
@@ -36,6 +36,9 @@ public static class ErrorCodes
     public const string DeviceNotFound = "141";
     public const string DeviceTokenDuplicate = "142";
 
+    // === Message (5) ===
+    public const string MessageNotFound = "151";
+
     // === Push (6) ===
     public const string PushSendFailed = "161";
     public const string PushStateChangeNotAllowed = "162";