Joseph-Alfred Mousseau PC (July 17, 1837 – March 30, 1886), was a Canadian lawyer and politician, who served in the federal Cabinet and also as the sixth premier of Quebec.

Exchanging places with Joseph-Adolphe Chapleau, Mousseau left federal politics to become the sixth Premier of the province of Quebec from July 31, 1882.

He served until his resignation on January 22, 1884, after being appointed as a puisne judge of the Superior Court for the district of Rimouski.

His brother Joseph Octave Mousseau was also a member of the Canadian House of Commons.

This article about a Quebec Member of Parliament from the Conservative Party of Canada (1867–1942) is a stub.