In 1996, he was named the Volleyball Magazine National Freshman of the Year and was a Third-Team All-Mountain Pacific Sports Federation (MPSF).

In 1999, he was named the MPSF Player of the Year and was a First Team American Volleyball Coaches Association (AVCA) All-American.

In 1998, he finished second in the nation in blocks per game (2.02) en route to repeating as a First Team All-American.

In 1999, he capped off his successful career by leading BYU to the program's first ever NCAA Men's Volleyball Championship and was once again a First Team All-American as he ranked first in the country in hitting percentage (.498) and blocks per game (2.14) In July 2006, Millar was named as an assistant coach for the BYU men's volleyball team under Head Coach Tom Peterson.

In August 2006, Millar was named co-interim head coach of the BYU men's volleyball team after Peterson's sudden resignation.