M61火神式机炮（M61 Vulcan，中文通常简称成M61机炮、火神炮）是一种由美军开发的六管连发机关砲，经常被装载在战斗机、直升机上作为高射速近距离火砲系统。通用代号GAU-4（GAU是「航空用火炮」，Gun, Aircraft Unit的缩写），口径为20mm，其航空用版本被赋予M61的代号，与M39同为美**机上常见的固定武装。美国海军航部队使用包括M61A1与M61A2在内，两种规格稍有不同的版本，而美国空军的F-16和****的经国号等战机则搭载了轻量化的M61A1机炮版本。

The M61 Vulcan is a hydraulically or pneumatically driven, six-barrel, air-cooled, electrically fired Gatling-style rotary cannon which fires 20 mm rounds at an extremely high rate (typically 6,000 rounds per minute). The M61 and its derivatives have been the principal cannon armament of United States military fixed-wing aircraft for fifty years.