Wallace was appointed classical master at Cupar Academy in 1854, shortly after graduating from university.

[1] In July 1857, he was licensed as a minister by the Presbytery of Edinburgh, and he was ordained at Newton-on-Ayr Church of Scotland in December.

As a result, his fitness to be a minister was questioned[3] and presumably this controversy influenced his decision to leave the clerical profession in August 1876.

[5] After leaving his clerical role, Wallace was appointed editor of The Scotsman newspaper, a position he held until November 1880.

[2] In November 1883 he studied law and called the English Bar at the Middle Temple, London.