Whitehead negotiated the plea with prosecutors at his Monday arraignment, stemming from an incident that occurred in April 2010 at his Las Vegas home.
Whitehead will not be sentenced until January 19, 2012. According to the Las Vegas Sun, he is expected to receive probation, but could receive a prison term of up to 20 years.
According to the Sun, the victim told police that she and a friend had visited Whitehead's home for a barbecue and stayed there after drinking.
Whitehead reportedly told the women they could sleep in his bed. One of the women said she awoke some time later to find her pants down and Whitehead having sex with her. According to the police report, she asked him to stop, but he continued for three minutes before stopping.
Under the Alford doctrine, a defendant does not admit his guilt to the crime, but acknowledges that the prosecutor has enough evidence to convince a jury to convict him of the offense.
Attempted sexual assault is a class B felony in Nevada, and judge Melissa De La Garza told Whitehead that by virtue of his guilty plea, he would be subject to lifetime supervision and be required to register as a sex offender.
Whitehead had originally been charged with sexual assault, attempted sexual assault, and open and gross lewdness, as well as drug charges involving marijuana that had been found growing in his home.
A former Ultimate Fighter season two cast member, Whitehead has competed in promotions ranging from the WEC to the IFL to Strikeforce. A 10-year veteran of the sport, he holds a 26-7 career record.
Since his arrest, he has competed twice, winning bouts against Chase Gormley and Eddie Sanchez.