James J. Bruin (October 31, 1898 – January 26, 1949) was an American politician from Lowell, Massachusetts.

[1] Bruin served on the Lowell school committee from 1923 to 1925.

[1] In 1932 he was the Democratic nominee for the United States House of Representatives seat in Massachusetts's 5th congressional district, but lost to incumbent Edith Nourse Rogers.

[1] In 1934 he was the Democratic nominee for Middlesex County District Attorney, but lost to incumbent Warren L.

[2] In 1948, Bruin returned to elected office as a member of the Lowell city council.