He was born at Paterson's Court in the Broughton district[3] of Edinburgh, the son of James Bonar (1758–1821), a solicitor with the Excise, and his wife Marjory Pyott Maitland (1753–1834).

With Robert Murray McCheyne he visited Palestine in 1839 to inquire into the condition of the Jews there.

He served as minister of Finnieston Free Church, Glasgow, from 1856 till his death.

Bonar was identified with evangelical and revival movements and adhered to the doctrine of premillennialism.

[citation needed] He married on 4 April 1848, Isabella (died 14 October 1864), youngest daughter of James Dickson, stationer, Edinburgh, and had issue — while the Reminiscences are available separately as: