Zamil Offshore Services Company (ZOSCO) is a prominent Saudi company specializing in offshore and marine services. Established in 1977 by the Zamil brothers, it is part of the Zamil Group Holding, a major conglomerate in Saudi Arabia. ZOSCO has grown to become the largest offshore support vessel operator in the Middle East and the fifth largest globally, with a workforce of over 3,600 employees.

The company operates a diverse fleet of approximately 75 offshore support vessels, including jack-up barges, platform supply vessels, and accommodation support vessels. ZOSCO provides a range of services, such as chartering and operating specialized vessels, offshore hook-up projects, shipbuilding, and marine logistics support. It also manages three shipyards in Dammam and Jeddah, focusing on shipbuilding and maintenance. ZOSCO's primary customer is Saudi Aramco, with additional clients in Qatar, the UAE, and various marine authorities. The company aims to lead the offshore and marine services sector in the Middle East and selected global markets.