Daughter of Madeleine Bélanger, MNA for Mégantic-Compton from 1983 to 2003, Johanne Gonthier served major Canadian corporations in her role as public relations, communications and marketing specialist. She occupied many key positions within the ranks of the management team at Houston/Edelman Public Relations Worldwide, including 10 years as vice-president.

Back in the Lac Mégantic area in 2001, Mrs Gonthier served as Executive director of the Lac Mégantic Chamber of Commerce from 2003 until 2007, when she decided to enter politics.

Since joining the National Assembly, in April 2007, Mrs. Gonthier has held different functions. Entrusted with the position of Parliamentary assistant to the Minister of Employment and Social Solidarity in January 2009. She is also member of the Committee on Labour and the Economy since September 15, 2009 as well as member of the Committee on Agriculture, Fisheries, Energy and Natural Resources since December 1, 2009. In February 2011, she was appointed Temporary Committee Chair.