
Pemilik terakhirnya adalah Robert King, seorang pedagang Quaker Amerika Serikat yang mengizinkan Equiano untuk berdagang. Equiano berhasil membeli kebebasannya pada tahun 1766. Equiano menetap di Inggris pada tahun 1767 dan bekerja dan berkelana selama dua puluh tahun sebagai pelaut, pedagang dan penjelajah di Karibia, Arktik, Tiga Belas Koloni, Amerika Tengah dan Selatan, serta Britania Raya.
Setelah menetap di London, Equiano menikahi seorang perempuan Inggris yang bernama Susannah Cullen pada tahun 1792 dan mereka dikaruniai dua orang anak. Di London, Equiano merupakan anggota Sons of Africa, kelompok abolisionis yang terdiri dari orang-orang Afrika yang tinggal di Britania, dan ia merupakan pemimpin pergerakan anti-budak yang penting pada tahun 1780-an.
Sebagai seorang manusia yang bebas, hidup Equiano penuh dengan rasa stres; ia terus menurus terpikir untuk bunuh diri hingga ia akhirnya menganut agama Kristen Protestan. Ia meninggal pada tahun 1797 di London, tetapi lokasi kuburannya tidak diketahui. Kematiannya diliput oleh koran Britania dan Amerika. Semenjak tahun 1967, memoirnya telah dianggap sebagai "permulaan sastra Afrika modern yang sesungguhnya".
In London, Equiano (identifying as Gustavus Vassa during his lifetime) was part of the Sons of Africa, an abolitionist group composed of prominent Africans living in Britain, and he was active among leaders of the anti-slave trade movement in the 1780s. He published his autobiography, The Interesting Narrative of the Life of Olaudah Equiano (1789), which depicted the horrors of slavery. It went through nine editions and aided passage of the British Slave Trade Act of 1807, which abolished the African slave trade.
As a free man, Equiano had a stressful life; he had suffered suicidal thoughts before he became a Protestant Christian and found peace in his faith. After settling in London, Equiano married an English woman named Susannah Cullen in 1792 and they had two daughters. He died in 1797 in London; his gravesite is unknown. Equiano's death was recognized in Britain as well as by American newspapers. Plaques commemorating his life have been placed at buildings where he lived in London. Since the late 20th century, when his autobiography was published in a new edition, he has been increasingly studied by a range of scholars, including many from his supposed homeland of Nigeria.