Orgeron, who has served as USC's defensive line coach and recruiting coordinator, takes over after Haden revealed earlier in the day Kiffin had been let go after losing seven of his last 11 games dating back to last season, including Saturday's 62-41 defeat at Arizona State.
"Our history has been great, and we need to be great again," Haden told USA Today. "My job is to do what is best for USC, I personally have a great deal of respect for Lane. ... He did the absolute best he can.
"Lane was clearly disappointed. He really, really tried to keep his job."
Orgeron went 10-25 from 2005-07 as head coach at Mississippi.
The Trojans are 3-2 this season with both losses against PAC-12 rivals. Kiffin compiled a 28-15 record in four seasons since replacing Pete Carroll, who had built USC into a national championship contender.
Kiffin was an assistant under Carroll, but inherited a lot of baggage from his high-flying era after Carroll departed for the Seattle Seahawks in 2010. The biggest blow was harsh NCAA sanctions stemming from the Reggie Bush recruiting scandal. It included a two-year bowl ban and the loss of 30 scholarships over three years.
After going 10-2 in his first season as head coach, Kiffin stumbled to 7-6 last season, which put him on the media's pre-season hot seat.