diff --git a/hal/include/HAL/cpp/Semaphore.h b/hal/include/HAL/cpp/Semaphore.h
deleted file mode 100644
index 53e17d7194..0000000000
--- a/hal/include/HAL/cpp/Semaphore.h
+++ /dev/null
@@ -1,41 +0,0 @@
-/*----------------------------------------------------------------------------*/
-/* Copyright (c) FIRST 2016-2017. All Rights Reserved.                        */
-/* Open Source Software - may be modified and shared by FRC teams. The code   */
-/* must be accompanied by the FIRST BSD license file in the root directory of */
-/* the project.                                                               */
-/*----------------------------------------------------------------------------*/
-
-#pragma once
-
-#include <stdint.h>
-
-#include <condition_variable>
-
-#include "HAL/cpp/priority_mutex.h"
-#include "support/deprecated.h"
-
-class WPI_DEPRECATED(
-    "Semaphore scheduled for removal in 2018. Recommended to replace with a "
-    "std::mutex and std::condition_variable") Semaphore {
- public:
-  explicit Semaphore(int32_t count = 0);
-  Semaphore(Semaphore&&);
-  Semaphore& operator=(Semaphore&&);
-
-  void give();
-  void take();
-
-  // @return true if semaphore was locked successfully. false if not.
-  bool tryTake();
-
-  static const int32_t kNoWait = 0;
-  static const int32_t kWaitForever = -1;
-
-  static const int32_t kEmpty = 0;
-  static const int32_t kFull = 1;
-
- private:
-  priority_mutex m_mutex;
-  std::condition_variable_any m_condition;
-  int32_t m_count = 0;
-};
diff --git a/hal/lib/athena/cpp/Semaphore.cpp b/hal/lib/athena/cpp/Semaphore.cpp
deleted file mode 100644
index 521c816b7c..0000000000
--- a/hal/lib/athena/cpp/Semaphore.cpp
+++ /dev/null
@@ -1,32 +0,0 @@
-/*----------------------------------------------------------------------------*/
-/* Copyright (c) FIRST 2015-2017. All Rights Reserved.                        */
-/* Open Source Software - may be modified and shared by FRC teams. The code   */
-/* must be accompanied by the FIRST BSD license file in the root directory of */
-/* the project.                                                               */
-/*----------------------------------------------------------------------------*/
-
-#include "HAL/cpp/Semaphore.h"
-
-Semaphore::Semaphore(int32_t count) { m_count = count; }
-
-void Semaphore::give() {
-  std::lock_guard<priority_mutex> lock(m_mutex);
-  ++m_count;
-  m_condition.notify_one();
-}
-
-void Semaphore::take() {
-  std::unique_lock<priority_mutex> lock(m_mutex);
-  m_condition.wait(lock, [this] { return m_count; });
-  --m_count;
-}
-
-bool Semaphore::tryTake() {
-  std::lock_guard<priority_mutex> lock(m_mutex);
-  if (m_count) {
-    --m_count;
-    return true;
-  } else {
-    return false;
-  }
-}