Barnabas Bidwell (August 23, 1763 - July 27, 1833) was a dual Canadian and American politican of the 19th Century.
Born in Tyringham (now Monterey), Massachusetts and graduated from Yale College in 1785. He later attended Brown University in Providence, Rhode Island. He was admitted to the Massachusetts state bar in 1805 and commenced practice in Stockbridge, Massachusetts.
He was a Massachusetts State Senator from 1801-1804, Massachusetts House of Representatives from 1805-1807. Bidwell was elected as a Republican and served in the Ninth and Tenth Congresses (March 4, 1805 - July 13, 1807). He was Attorney General of Massachusetts (June 15, 1807 - August 30, 1810).
The Bidwells moved to Canada in about 1812 and settled in Kingston, Ontario.
He won a seat in the Legislative Assembly of Upper Canada for Lennox and Addington, but failed to take his seat. He died in Bath, Ontario, and his remains are interred in Cataraqui Cemetery, Cataraqui, Ontario.
His son Marshall Spring Bidwell successfully sat in the same seat from 1824 to 1836. He too left for the United States.