A.P. Moller–Maersk Group, also known as simply Maersk, it is a Danish business conglomerate with activities in the transport, logistics and energy sectors. Maersk has been the largest container ship and supply vessel operator in the world since 1996. The company is based in Copenhagen, Denmark, with subsidiaries and offices across 130 countries and around 88,000 employees.

In September 2016, Maersk Group announced splitting into two separate divisions: transport & logistics and energy. The company's 2017 annual revenue was US$35 billion (2017).

It operates through subsidiaries within six main business units. Container shipping and related activities comprise Maersk Line, Safmarine, MCC, Damco and Container Inland Services. APM Terminals involve container terminal activities. Tankers, offshore and other shipping activities include Maersk Tankers, Maersk Drilling, Maersk Floating Production, Storage and Offloading (FPSO), Maersk Supply Service, Svitzer and Norfolkline, among others. Oil and gas activities encompass Maersk Oil. Retail activity comprises The Dansk Supermarked Group. Shipyards, other industrial companies, interest in Danske Bank A/S, etc. include The Odense Steel Shipyard Group, Rosti, Star Air and a 20% stake in Danske Bank. The A.P. Moller - Maersk Group comprises approximately 1,100 companies.

Maersk Line operates over 450 vessels and Safmarine is an independently fleet of more than 40 container vessels.