Callejas, 72, who is also a former head of Honduran football, made his guilty plea in a federal court in New York.
Each count carries a maximum sentence of 20 years in prison.
Callejas, who was president of Honduras from 1990 to 1994, flew to the US in December to face the indictments.
At a court appearance in December, he pleaded not guilty to the charges.
But in court on Monday, he told the judge that he had accepted bribes and distributed some of the money to others, AP news agency reported.
“I knew it was wrong,” he told the court.
According to one of the indictments, a marketing firm wired $500,000 (£350,000) in 2012 to a Panama bank account in order for it to be paid as bribes to Callejas and another football official in exchange for broadcasting rights to qualifier matches for the 2022 World Cup.
Callejas will be sentenced in August.
The US is investigating 42 people and organisations suspected of involvement in seeking bribes in return for lucrative marketing rights.
