Pierre Lorrain (April 21, 1942 – December 24, 2004) was a lawyer and political figure in Quebec.
He represented Saint-Jean in the Quebec National Assembly from 1985 to 1989 as a Liberal.
He was born in Farnham, Quebec, the son of Roch Lorrain and Jeanne Marcil, and was educated at the Collège Roussin and the Université de Sherbrooke.
Lorrain was admitted to the Quebec bar in 1973 and practised law in Saint-Jean-sur-Richelieu.
Lorrain served as President of the National Assembly from 1985 to 1989.