Yost has coached for 23 years. Along with Oregon, he's also made professional stops at Missouri, Washington State and Toledo.
"We're excited to hire coach Yost," USU head coach Matt Wells said in a statement. "His pedigree and background as a quarterback coach and his ability to develop explosive offenses will be very exciting for our fans and players alike."
Utah State finished 3-9 last season, including 1-7 in the Mountain West Conference. The Aggies failed to reach a bowl game for the first time in six years.
"I'm very grateful for this opportunity and for the confidence that coach Wells has shown in me," said Yost. "Being an offensive coordinator is a big responsibility and I'm looking forward to helping Utah State football."
In Yost's one season at Oregon, the Ducks ranked 16th nationally in total offense (491.7). They also ranked 27th in scoring (35.4) and rushing (226.4). Oregon quarterbacks threw only six interceptions.
Yost graduated from Kent State in 1992. He started his coaching career at Carrollton (Ohio) High School.
Last season, Utah State listed wide receivers coach Jovon Bouknight and quarterbacks coach/recruiting coordinator Luke Wells as co-offensive coordinators. Mike Canales was the assistant head coach/quarterbacks coach.
All three remain on the staff.
Bouknight stays as the receivers coach. Luke Wells will be the recruiting coordinator-tight ends coach. Canales will be the assistant head coach-running back coach.
On Thursday, Utah State announced linebackers coach David Kotulski would not return. His replacement has not been named.