"We are excited that Taysom has decided to come to BYU," said coach Bronco Mendenhall. "He is a fantastic football player and an outstanding individual, and we look forward to having him join our program in January."
Current BYU quarterback Riley Nelson, from Logan High, signed with Utah State out of high school and played for the Aggies his freshman year before deciding to transfer to BYU while on his mission in Spain.
Hill was the All-Idaho 5A Player of the Year and Gatorade High School Player of the Year after his senior season in 2008.
He completed 166 of 258 passes for 2,269 yards and 18 touchdowns as a senior, when he was listed at 6-foot-2, 210 pounds.
"Taysom is an outstanding quarterback," BYU offensive coordinator Brandon Doman said. "He will be a great future asset to our program."
Earlier this week, the BYU football program received a commitment from Tanner Mangum, a junior at Idaho's Eagle High School, near Boise. Mangum chose BYU over offers from Boise State, Utah and others, but is expected to go on a church mission before enrolling.