|Born||23 December 1981|
|Height||5 feet 7 inches (1.70 m)|
|Weight||127 pounds (58 kg)|
|College team||Cal Poly-San Luis Obispo Mustangs|
|Coached by||Rose Monday|
|Achievements and titles|
|World finals||2009, 800 m,
7th in Semi-finals
2011, 800 m,
6th in finals
|Personal best(s)||800 m: 1:57.84|
At the 2008 U.S. Olympic Trials, Vessey finished 5th in the 800 m, with a time of 2:02.01. In June 2009, Vessey was a surprise winner at the Prefontaine Classic, in 2:00.18. The race director said Vessey "was a last-minute, last-minute add. One step above a field-filler". The competition included Olympic gold medalist Pamela Jelimo.
Vessey continued her impressive results in 2009. At the Herculis meet in Monaco, she won the race with a time of 1:57.84. At the time, this was the fastest 800 m performance for the year, and tied for the seventh fastest by an American runner. This result earned Vessey a place on the US 2009 World Championship team—she finished 4th at the 2009 U.S. Championships, and needed to break 2:00 to earn an "A" standard.
At the 2009 World Championships, Vessey finished seventh in the 800 m semifinal with a time of 2:03.55. At the 2011 World Championships, Vessey finished sixth in the 800 with a time of 1:58.50. At the 2009 IAAF World Athletics Final in Greece, Vessey took 2nd and the Silver in a time of 2:00.31.
In 2011, masters runner Rose Monday became Vessey's coach. She qualified for the finals of the 800 m at the 2011 World Championships in Athletics, where she finished sixth. A week later, Vessey won the 800 m in 1:58.64 at the Hanžeković Memorial as part of the IAAF World Challenge Meetings.
At the 2012 US Olympic trials, Vessey finished eighth in 2:03.44.
On December 21, 2012 Vessey accepted a public warning and loss of results for testing positive for canrenone. She admitted to taking a prescribed skincare product, but was not aware that it contained a diuretic. 
- Gambaccini, Peter. "A Brief Chat With Maggie Vessey". Runner's World. Retrieved 2009-08-04.
- "Runner's World: Racing News". Runner's World. Retrieved 2009-08-04.
- Masuda, Andrew (August 4, 2009). "Cal Poly alum Maggie Vessey officially headed to World Championships". KSBY.com. Retrieved 2009-08-04.
- Battaglia, Joe (July 29, 2009). "Inside Track: Vessey's incredible journey". Universal Sports.
- "Runner's World: Racing News". Runner's World. 2009-08-18. Retrieved 2009-08-18.
- "Runner's World: Racing News". Runner's World. 2011-03-31. Retrieved 2011-05-30.
- Ritchie, Steve. "World Track and Field Championships: Soquel's Vessey sees quest for 800-meter medal end in bittersweet final". Santa Cruz Sentinel. Retrieved 14 September 2011.
- "Local roundup: Soquel's Vessey wins 800 in Croatia". Santa Cruz Sentinel. Retrieved 14 September 2011.
- USATF 2012 Olympic Trials results
- US Track & Field Athlete, Vessey, Accepts Public Warning For Rule Violation