Foster was born in North Shields, England of a primarily Quaker family, but his family moved south to London in 1830, where his father founded M. B. Foster & sons — a successful beer-bottling company. He was schooled at Hitchin, Hertfordshire and on leaving initially went into his fathers business. However, noticing his talent for art, his father secured an apprenticeship with the notable wood engraver, Ebenezer Landells, where he worked on illustrations for Punch magazine and the Illustrated London News.
On leaving Landells employ, he continued to produce work for the Illustrated London News and the Illustrated London Almanack. He also found work as a book illustrator and, during the 1850s, trained himself to paint in watercolours. His illustrations of Longfellow’s Evangeline and books of poetry by other contemporaries were a great success, and he quickly became a successful artist in watercolours. Birket Foster became an Associate of the "Old" Watercolour Society (Later the Royal Watercolour Society) in 1860 and exhibited some 400 of his paintings at the Royal Academy over more than 2 decades.