The person spoke to The Associated Press on the condition of anonymity Monday because the school hadn't announced the hiring, which ends a two-week search by Colorado that included a rejection by its first choice, Butch Jones.
MacIntyre will be asked to turn around a program that's had seven straight losing seasons, including a 1-11 record this year that was the worst in the 123-year history of the program.
He's done it before: The Spartans (10-2) are ranked No. 25 in the BCS and are heading to the Dec. 27 Military Bowl in Washington, D.C., two years after a 1-12 showing in his first season.
McIntyre, the son of former Vanderbilt coach George MacIntyre, is 16-21 in his three years as a head coach at San Jose State after serving as Duke's defensive coordinator and working as a secondary coach for the Dallas Cowboys and New York Jets.
The 47-year-old MacIntyre took over a Spartans program still reeling from limited scholarships following academic penalties by the NCAA stemming from problems before previous coach Dick Tomey arrived. After the 1-12 season featuring a heavy schedule of ranked teams, the Spartans went 5-7 in MacIntyre's second season.
MacIntyre will be succeeding Jon Embree at Colorado.
Last week, Jones rejected a five-year, $13.5 million offer that would have made him the highest-paid coach in CU history, and instead took the vacant head coaching job at Tennessee. Jones also had been promised upgrades at Folsom Field and the team's training center.
This marks athletic director Mike Bohn's third head coaching hire since he fired Gary Barnett in 2005. Embree had three years remaining on a five-year contract when he was fired after going 4-21.
The Buffaloes job isn't a glamorous one, with sub-par football facilities and a fan base and booster pool disenchanted by seven straight losing seasons - and now, as Embree's quick hook attests, an administration that wants immediate upgrades on the scoreboard and in the Pac-12 standings.
The new coach faces a truncated recruiting season and must try to keep defections to a minimum from a roster that's loaded with freshmen.