Joseph-Rosaire Thibaudeau (October 1, 1837 – June 16, 1909) was a Quebec businessman and political figure. He was aLiberal member of the Senate of Canada for Rigaud division from 1878 to 1909.

He was born at Cap-Santé, Lower Canada in 1837. Thibaudeau operated the Montreal branch of his older brother Isidore's company until 1895.^[1] In 1890, he was named sheriff for the city of Montreal. He was also president of the electric company and vice-president of the telephone company.

Thibaudeau was a member of the first Board of directors, The Northern Electric and Manufacturing Company (Nortel).^{[citation needed]}

His nephew Alfred Thibaudeau also served in the Canadian senate.