徕卡（Leica）是一家著名的德国公司生产的相机的品牌，由莱茨（Leitz）和相机（camera）的前音节组成。公司的原名为恩斯特·徕茨公司，目前拆分为三家公司：徕卡相机、徕卡测量系统和徕卡显微系统，分别生产相机、空间信息测量设备和显微镜。“徕卡”品牌由徕卡显微系统持有，并授权另两家公司使用。其常见数码相机镜头产品注册商标Summarit，为一套质量标准检测和保证体系，有授权其他厂商使用。

徕卡相机最初问世于1925年，是世界上最早的35mm相机。也是最早确立35mm软片格式（24mmX36mm）。

Leica Camera AG (pronounced[ˈlaɪka]), is a German optics enterprise and manufacturer of Leica cameras. The company is primarily known for its high-quality, lightweight rangefinder cameras, which have gained renown from their use as the camera of choice for several famous street photographers. The predecessor of the company, formerly known as Ernst Leitz GmbH, is now three companies: Leica Camera AG, Leica Geosystems AG, and Leica Microsystems GmbH, which manufacture cameras, geosurvey equipment, and microscopes, respectively. Leica Microsystems AG owns the Leica brand and licenses the sister companies to use it.