倾转旋翼机（英语：Tiltrotor），也叫可倾斜旋翼机或倾转旋翼飞机），是一种同时具有旋翼和固定翼，并在机翼两侧翼梢处各安装有一套可在水平和垂直位置之间转动的可倾转旋翼系统的航空器。倾转旋翼机在引擎旋转到垂直位置时相当于横列式直升机，可进行垂直起降、悬停、低速空中盘旋等直升机的飞行动作；而在引擎旋转至水平位置时相当于固定翼飞机螺旋桨飞机，可实现比直升机更快的航速。以上特点使得倾转旋翼机兼具直升机和固定翼飞机的优点，应用前景十分看好。美国海军的V-22鱼鹰式倾转旋翼机是目前世界上唯一一款具有实用价值的倾转旋翼机。

A tiltrotor is an aircraft which generates lift and propulsion by way of one or more powered rotors (sometimes called proprotors) mounted on rotating engine pods or nacelles usually at the ends of a fixed wing or an engine mounted in the fuselage with drive shafts transferring power to rotor assemblies mounted on the wingtips. It combines the vertical lift capability of a helicopter with the speed and range of a conventional fixed-wing aircraft. For vertical flight, the rotors are angled so the plane of rotation is horizontal, lifting the way a helicopter rotor does. As the aircraft gains speed, the rotors are progressively tilted forward, with the plane of rotation eventually becoming vertical. In this mode the wing provides the lift, and the rotor provides thrust as a propeller. Since the rotors can be configured to be more efficient for propulsion (e.g. with root-tip twist) and it avoids a helicopter's issues of retreating blade stall, the tiltrotor can achieve higher speeds than helicopters.