Adam Crooks was born on December 11, 1827, in West Flamborough, Ontario.

He was a lawyer and politician. He studied at Upper Canada College and the University of Toronto (B.C.L, 1851; B.A., 1852; M.A., 1853). He was called to the bar in 1851. Practising in Toronto, he specialized in the remunerative field of equity law. His most famous case, in 1862, the Commercial Bank of Canada v. the Great Western Railway Company, was a $900,000 civil suit. He received a D.C.L. from the University of Toronto and was named a Queen's Counsel in 1863. He served as Attorney General from 1871 to 1872 and provincial treasurer from 1872 to 1877. Crooks played a major role in developing the 1876 liquor licence act, also known as the Crooks Act, which attempted to control the sale of alcohol within the province. He also served as the first Minister of Education in Ontario (1876-1883). In 1884, he suffered a decline in mental and physical health, and by the fall of 1884, he was confined to an asylum in Hartford, Conn., where he died in 1885.

In 1856, he married Emily Anne C. Evans (1828–1868). He died on December 28, 1885, in Hartford, Connecticut.