Mary Anne Theisen-Lappen (born November 3, 1990) is an American weightlifter.
She won the silver medal in the women's +87kg event at the 2023 World Weightlifting Championships held in Riyadh, Saudi Arabia, and the gold medal in the women's +81kg event at the 2023 Pan American Games held in Santiago, Chile.
In 2021, she won the gold medal in the women's +87kg event at the Pan American Weightlifting Championships held in Guayaquil, Ecuador. She also won the gold medal in her event at the 2023 Pan American Weightlifting Championships held in Bariloche, Argentina.
In September 2023, Theisen-Lappen won the silver medal in the women's +87kg event at the World Weightlifting Championships held in Riyadh, Saudi Arabia.
In October 2023, she won the gold medal in the women's +81kg event at the Pan American Games held in Santiago, Chile. She made six successful lifts with her best lifts being 120kg in the Snatch and 157kg in the Clean & Jerk.
In December 2023, Theisen-Lappen won the gold medal in the women's +87 kg at the 2023 IWF Grand Prix II in Doha, Qatar, with a total of 283kg.
In August 2024, she finished in 5th place in the women's +81kg event at the 2024 Summer Olympics held in Paris, France.
She is married to bowler Casey Lappen.