Campaign officials announced Tuesday that the first debate is scheduled for Oct. 10 in Phoenix with the second in Tucson on Oct. 15 and the third in Yuma on Oct. 25.
Carmona and Flake face off in the November general election to succeed retiring Republican Sen. Jon Kyl.
Flake is a six-term congressman. Carmona was surgeon general under President George W. Bush.
The outcome of the widely watched race between Carmona and Flake could determine whether the Senate is controlled by Democrats or Republicans. If the GOP picks up four Senate seats in the November elections, it would have a majority.