The Douglas County District Court jury deliberated for 4 hours Thursday and 2 hours Friday before returning its verdict, The Denver Post reported.
Cox had been charged with sexually assaulting a victim who was unable to assess her condition. The alleged victim, who became pregnant by Cox, testified she believed she had been drugged in Cox's Lone Tree home during Labor Day weekend 2010.
The Post said she cried and stomped her feet upon hearing the verdict.
There were no witnesses to the alleged attack, and the woman did not have a rape kit performed when she briefly sought treatment at a hospital, before leaving when she learned hospital staff called police.
"There are no winners and no losers in this situation," said Cox's attorney, Harvey Steinberg. "We just hope everyone can get on with their lives."
Cox told reporters he felt "great" about the verdict. He had faced a possible sentence of life in prison if found guilty.
"I'm grateful for all of my supporters," he said.
"The feeling i have right now can never b felt, cant b explained, the lord has his ways of work, glad i was able 2 b in the path of that!!" Cox wrote later on Twitter.