John Foster, Junior (circa 1787 – 26 September 1846) was an English architect.
Foster studied under Jeffry Wyatt in London and in 1809 travelled in the eastern Mediterranean. During 1810-11 he accompanied C. R. Cockerell and the German archaeologists Haller and Linckh in their excavation of the temples at Aegina and Bassae.[1] He returned to Liverpool in 1816 and joined the family building firm. He succeeded his father (who bore the same name) as Senior Surveyor to the Corporation of Liverpool in 1824, and held that post until the Municipal Reform Act of 1834. His own designs included The Oratory and the dramatic St James Cemetery, both in the grounds of Liverpool Cathedral and St. Andrew's in Rodney Street, now derelict. The second Royal Infirmary and the public baths have both been demolished, as has the enormous, domed Custom House, which suffered superficial bomb damage during WWII. He is often attributed as the architect for numbers 2-10 Gambier Terrace, Liverpool.