国际海事卫星组织（英语：Inmarsat plc, International Maritime Satellite Organization ）（LSE：ISAT）是英国的卫星通信公司，提供全球性的移动服务。以11个地球静止轨道通信卫星，通过便携式或移动终端进行通信地面站，为世界各地的用户提供电话和数据服务。国际海事卫星组织的网络提供政府、援助机构、媒体和企业需要在偏远地区或有没有可靠的地面网络通信的范围提供通信服务。该公司在伦敦证券交易所上市，2011年12月以来是富时250指数的组成股。

Inmarsat plc (LSE: ISAT) is a British satellite telecommunications company, offering global mobile services. It provides telephone and data services to users worldwide, via portable or mobile terminals which communicate with ground stations through twelve geostationary telecommunications satellites. Inmarsat's network provides communications services to a range of governments, aid agencies, media outlets and businesses with a need to communicate in remote regions or where there is no reliable terrestrial network. The company is listed on the London Stock Exchange, is a constituent of the FTSE 100 Index and a financial (as well as technical) sponsor of Télécoms Sans Frontières.