Knibb found six English Baptist missionaries, African-Caribbean Baptist deacons, and thriving congregations already in Jamaica when he arrived. Together they were following the pioneering work of the African preacher George Lisle, a former slave from Virginia who had arrived in 1782 and founded a Baptist church in Kingston. Knibb began work as the schoolmaster of the Baptist mission school in Kingston and worked closely with fellow missionaries Thomas Burchell and James Phillippo, who formed a trio. In 1828 he moved to Savanna-la-Mar. In 1830 he became the minister responsible for the Baptist church at Falmouth, which had regular congregations of 600 when he arrived. He remained there as minister until he died.