固态电子器件（英语：Solid-state electronics）是指那些完全使用固体电子材料、并利用束缚于其内电子或者其他载流子导电的电路器件。这一概念经常用来与早期的技术如真空管等作比较。并且，“固态”一词还特别地将电子-机械综合设备，例如继电器、开关和硬盘，和其他具有活动件的设备排除开外。虽然固态电子器件材料包括结晶体、多晶体、无定形体，并且包括导体、绝缘体和半导体，固态电子器件还是以结晶半导体为主。

通常的固态器件包括晶体管、微处理器芯片以及动态随机访问存储器（Dynamic random-access memory (DRAM)）等。动态随机访问存储器在计算机及其相关产品中应用广泛，而且最近的固态硬盘有取代传统机械旋转式硬盘的趋势。固态电子器件的行为涉及了大量的电磁学、量子力学过程。固态电子器件的概念在1950年代和1960年代开始变得流行，那段时间业界经历了真空管到半导体二极管和之后的晶体管的技术转变。后来，集成电路（integrated circuit (IC)）、发光二极管（light-emitting diode (LED)）以及液晶显示器（liquid-crystal display (LCD)）等成为了固态电子设备研究的新成果。

Solid-state electronics are those circuits or devices built entirely from solid materials and in which the electrons, or other charge carriers, are confined entirely within the solid material. The term is often used to contrast with the earlier technologies of vacuum and gas-discharge tube devices, and it is also conventional to exclude electro-mechanical devices (relays, switches, hard drives and other devices with moving parts) from the term solid state. While solid-state can include crystalline, polycrystalline and amorphous solids and refer to electrical conductors, insulators and semiconductors, the building material is most often a crystalline semiconductor. Common solid-state devices include transistors, microprocessor chips, and RAM. A specialized type of RAM called flash memory is used in flash drives and, more recently, solid-state drives to replace mechanically rotating magnetic disc hard drives. A considerable amount of electromagnetic and quantum-mechanical action takes place within the device. The expression became prevalent in the 1950s and the 1960s, during the transition from vacuum tube technology to semiconductor diodes and transistors. More recently, the integrated circuit (IC), the light-emitting diode (LED), and the liquid-crystal display (LCD) have evolved as further examples of solid-state devices.