多闸极晶体管指的是集合了多个闸极于一体的金氧半晶体管（MOSFET）。可以用一个电极来同时控制多闸极，亦可用多个电极单独控制各闸极。后者有时又被叫做Multiple Independent Gate Field Effect Transistor（MIGFET）。多闸极晶体管被提出为的是克服半导体工业里摩尔定律（Moore's law）发展至今体积的缩小已经到达物理极限的难题。

相当多的公司和机构已经在积极发展多闸极晶体管，其中包含了超微半导体，日立, IBM, 英飞凌，英特尔，台积电，飞思卡尔，加州大学伯克利分校等等，而ITRS预估多闸极晶体管将是32奈米以下重要的奠基石。实现上主要的障碍来自于制造技术，不论是平面和非平面的设计都面临挑战，特别是显影以及图案化技术。其他伴随发展的包含了信道应力、硅上绝缘以及高介电质/金属闸极材料。

A multigate device or multiple gate field-effect transistor (MuGFET) refers to a MOSFET (metal–oxide–semiconductor field-effect transistor) which incorporates more than one gate into a single device. The multiple gates may be controlled by a single gate electrode, wherein the multiple gate surfaces act electrically as a single gate, or by independent gate electrodes. A multigate device employing independent gate electrodes is sometimes called a Multiple Independent Gate Field Effect Transistor (MIGFET). Multigate transistors are one of the several strategies being developed by CMOS semiconductor manufacturers to create ever-smaller microprocessors and memory cells, colloquially referred to as extending Moore's Law.