Francis Barber was born a slave on a plantation in Jamaica in 1735. He was brought to England by his owner in 1750. After a brief schooling at a village school in Yorkshire he entered the service of his owner's son. Later he was hired out to Samuel Johnson after the death of his wife in 1752.

Barber worked as Johnson's valet until he ran away to sea in 1758. For the next two years he served on the HMS Stag in the North Sea. On his return in 1760 he rejoined Johnson's staff. Barber worked as Johnson's butler but after attending Bishop's Stortford Grammar School (1767-1772) he worked as his secretary.

Barber married an Englishwoman and the couple had four children. Barber and his family lived in Johnson's house. When Samuel Johnson died in 1784 he left Barber a gold watch and an annual payment of £70. Barber moved to Lichfield, Staffordshire, and later he became a schoolteacher in Burntwood.

Francis Barber died in 1801. His son, Samuel Barber (1785-1828), became a Primitive Methodist preacher in Staffordshire.