Octopus is a 126-metre (413 ft) megayacht built for Microsoft co-founder Paul Allen. She is one of the world's largest yachts. Launched in 2003 at a cost of $200 million, Octopus is a private vessel that has been loaned out for exploration projects, scientific research and rescue missions.

Paul Gardner Allen was an American businessman, computer programmer, researcher, investor, film producer, explorer, and philanthropist. He is best known for co-founding Microsoft Corporation with his childhood friend Bill Gates in 1975, which helped spark the microcomputer revolution of the 1970s and 1980s. Allen was ranked as the 44th-wealthiest person in the world by Forbes with an estimated net worth of $20.3 billion at the time of his death in October 2018.