Mary Spencer

Mary Spencer (born December 12, 1984) is a Canadian professional boxer who is a former WBA female super-welterweight champion. As an amateur she won three World Championships and a Pan American Games gold medal.

Amateur career Spencer competed in multiple sports as a child including basketball, volleyball, soccer and track and field. She began serious boxing training in 2002, eventually linking up with coach Charlie Stewart at the Windsor Amateur Boxing Club.

Spencer won three World Championships taking the 66 kg title in 2005 and 2008 then the 75 kg crown in 2010. She also won a gold medal at the 2011 Pan-American Games in Mexico defeating Yenebier Guillen of the Dominican Republic in the 75 kg final.

Considered a medal favourite at the London 2012 Summer Olympics, which were the first Games to include women's boxing, Spencer received a bye into the quarter-finals where she lost to China's Li Jinzi who she had beaten in the world championship final two years earlier.

Professional career Having turned professional after the Olympics, Spencer was undefeated in her first six pro-fights and in her seventh contest won the WBA female International and WBC female Silver super-welterweight titles with a first-round stoppage success over the previously unbeaten Mexican boxer Cynthia Lozano in Montreal, Canada, on 9 September 2022.

Next she took on Belgian boxer Femke Hermans for the vacant IBO female super-welterweight World title losing the bout in Shawnigan, Quebec, Canada, on 16 December 2022 by unanimous decision.

A rematch was held on 11 October 2023, in Montreal, Canada, with the IBO belt and the vacant IBF female super-welterweight title up for grabs. Once again Hermans got the victory, this time by majority decision.

Spencer snapped her losing streak with a win over Sonya Dreiling on 25 January 2024, taking victory via retirement when her American opponent failed to answer the bell at the start of round two.

WBA Super-Welterweight champion Spencer vs. Mannes On 5 September 2024 at Montreal Casino, Quebec, Canada, Spencer defeated Naomi Mannes by unanimous decision to win the interim WBA super-welterweight title.

Spencer vs. Suárez Spencer was elevated to a full champion after Terri Harper vacated the title. She made her first defense against Ogleidis Suárez back at Montreal Casino on 10 April 2025, winning by unanimous decision.

Unified Super-Welterweight Championship Spencer vs. Mayer Spencer defended her WBA title against Mikaela Mayer at Montreal Casino on 30 October 2025. The vacant WBC and WBO female super-welterweight championships were also on the line. Spencer lost by unanimous decision.

Unified Middleweight Championship Spencer vs. Robinson Spencer challenged Desley Robinson for her unified IBF and WBO middleweight titles at County Coliseum in El Paso, Texas, U.S. on May 30, 2026. She lost by unanimous decision.

Personal life Spencer was born in Wiarton, Ontario, Canada, and is a member of the Chippewas of Nawash Unceded First Nation formerly known as the Cape Croker First Nation. In January 2024, Spencer joined the Boxing Ontario board of directors.

Professional boxing record