James J. Bradley (born February 19, 1945 in Sudbury, Ontario) is a long-time Ontario Liberal Party politician and MPP in the Ontario legislature. Before entering politics, Bradley was a teacher with the Lincoln County Board of Education. He was elected to St. Catharines' city council in 1970, but also remained in the classroom until 1977.

After failed bids in the elections of 1967 and 1971, Bradley was first elected to the Ontario legislature in the 1977 election in the riding of St. Catharines, and has served as MPP for that riding since that time. He fended off strong challenges from the New Democratic Party in 1990 and the Progressive Conservative Party in 1995. On all other occasions since 1977, he has been re-elected without difficulty.

When the Liberals came to power under David Peterson following the 1985 Ontario election, Bradley became Minister of the Environment and held that position until the Liberals were defeated in the 1990 Ontario election. He was generally regarded as a committed Environment Minister, although many believed that his ambitions for the ministry were undermined by Peterson and Finance Minister Robert Nixon.

Bradley was a vocal opponent of David Peterson's plans to call an election in 1990, preferring that the party wait until 1992 before going to the polls. While the Liberals were defeated, Bradley was personally re-elected and had a prominent position in the Opposition benches.

When Nixon, the interim leader of the Liberals, left Queen's Park to accept an appointment he was replaced by Murray Elston. Elston resigned as interim leader to run in the 1992 Ontario Liberal Leadership Convention, and Bradley became interim leader of the party and interim Leader of the Opposition from November 1991 until the election of Lyn McLeod in February 1992. He remained an opposition stalwart until the Liberals won the 2003 Ontario election under Dalton McGuinty.

There was some speculation that Bradley would be re-appointed Minister of the Environment in McGuinty's government, but this did not occur. Instead, he was named Minister of Tourism and Recreation on October 23, 2003.