Mary Adah Akor Beasley (born September 24, 1976) is a Nigerian–American athlete who competed for the US at the 2005 and 2007 World Marathon Championships.

She was the sole runner on the John Muir High School cross country team and made it to the state meet.

[12][13] In the early fall of 2007, Akor was at the starting line of her second Marathon World Championship race, this time in Osaka, Japan.

[14][15] In 2005, Akor ran and placed second at Grandma's Marathon, a point-to-point race in Minnesota from Two Harbors to Duluth.

The year previous, she had placed 27th at the event's half marathon (named after local Olympian, Garry Bjorklund).

She ran 2:35:40 in the 70-degree heat to beat all women including Liza Hunter-Galvan and Russian Ramilya Burangulova and Tatyana Titova.

[17] It began a dominant streak, as she returned every June to win a total of three titles ('07, '08 in a headwind with a time of 2:41:43; and '09 in 2:36:52 en route to the medical tent for severe dehydration), defeating runners such as Zinaida Semenova, Violetta Kryza, Janet Cherobon, Alina Ivanova, Serkalem Abrha, and Robyn Friedman.

[6] She was named the third-best American woman marathoner in 2007 by Running Times magazine, behind Deena Kastor and Ann Alyanak (though she was ranked sixth-best by Track and Field News).

[21][2] She achieved her personal record time for the distance at the Twin Cities Marathon in October 2006, where she ran 2:33:50 for second place behind Marla Runyan and ahead of Zoila Gomez and Michelle Lilienthal.

[21] In 2009, at the Boston Marathon, Akor was in the top pace pack with Americans Kara Goucher and Elva Dryer, though Kenyan Salina Kosgei broke away for the win.

[23] Akor was considered a top American contender at the 2012 Boston Marathon along with Ruth Perkins and Lauren Philbrook.

[24] In the last month of 2012, at the Gobernador Marathon in Mexicali, Mexico, her drug test result showed use of Clenbuterol, a substance banned by the United States Anti-Doping Agency.

Security attempted to remove her from the stage while officials reminded her that she was ineligible to compete as top Nigerian because she had committed to run for the United States.

Still, she would collect wins and prize money since many race organizations didn't know or felt it would be unfair to withhold cash for the winner.

She wore a long-sleeve that obscured her bib, and she weaved over the road to prevent the second-place runner (Heather Lieberg) from passing her.

[25] By December, however, they adopted an anti-doping policy for their race that declared ineligible any athlete who had "ever been suspended for use of a prohibited substance by the USADA and/or WADA.

[40] Then she returned to the Baja California Marathon to re-establish her dominance, but finished second to Shewarge Amare Alene [es][41] Her race schedule continued strong into 2023.

She took the tape again, clocking 2:48:20 and collapsing at the finish line after edging Mexican athlete Estafany Velásquez by a few seconds.