Miller Farr graduated from Hebert High School in 1961 in Beaumont, Texas. At Hebert, Farr lettered in football, basketball, baseball, and track and was named All-State in football, baseball, and track. Farr attended Wichita State University on a scholarship, lettering in football and track. As a halfback, he led the nation in kickoff and punt returns and was named All-Conference. Farr was selected in the first round of the 1965 AFL Redshirt Draft by the Denver Broncos and, after his first season, moved to the San Diego Chargers in 1965. He later played for the Houston Oilers from 1967 through 1969.

​

Playing at cornerback, Farr was the AFL co-leader in interceptions with ten during the 1967 season, tying with two other players. The next year, Farr led the AFL in touchdown interceptions and earned First-Team All-AFL honors in both 1967 and 1968. Despite a bout with hepatitis, he intercepted two passes for touchdowns in one game in 1968. In 1970, Farr was involved in the first-ever trade between an AFL and NFL team—he and quarterback Pete Beathard were traded to St. Louis, while quarterback Charley Johnson and defensive back Bob Atkins were traded to Houston.

​

Farr joined the Detroit Lions in 1973 to play with his brother, Mel Farr. Miller was a six-time All-Pro selection and was chosen All-AFL in 1967, 1968, and 1969. He was also a three-time AFL All-Star and played in two AFL Championship games, in 1965 and 1967. Farr made 35 career interceptions in eight seasons, six of them for touchdowns. He established an AFL record for the most touchdowns from pass interceptions in a game (two) and tied the AFL record for interceptions returned for a touchdown in a season with three.

​

After retiring from football, Miller Farr became the general manager of a successful auto dealership in Michigan. He was one of sixteen professional football players honored with the Keys to the City of Beaumont in 1971, when Mayor Ken Ritter declared the Golden Triangle the "Football Capital of the World." Miller Farr is an inductee of the Museum of the Gulf Coast, Sports Hall of Fame.