Smith was born in Fayetteville, Arkansas, and grew up in Plano, Texas. He attended Plano Senior High School, and was a 2005 Plano Texas Hall of Honor inductee. In 1977, Smith helped Plano Senior High School win the Texas Class 4A state championship in front of a state record crowd just shy of 50,000 at Texas Stadium, a record that stands today.
At the University of Arkansas, Smith was a two-time consensus All-American selection, earning the honors in 1981 and 1982.
In 1982, he served as team captain, leading Arkansas to a 9–2–1 record and a victory over Florida in the Bluebonnet Bowl. He finished his career with 299 total tackles and still holds the Arkansas record for career tackles for loss, with 63.
He was a member of the Arkansas All-Decade Team and, in 1993, was voted into the Arkansas All-Century Team. Later, he was inducted into both the Arkansas State Hall of Fame (1995), and the Razorback Hall of Honor. Smith was inducted into the College Football Hall of Fame in 2000.
Smith was drafted by the San Diego Chargers in 1983. He was the 5th pick in the 1st round, and was the first defensive player taken in the 1983 draft. He was the Chargers team MVP in 1987, and the team defensive player of the year in 1985 and 1986. Smith was voted Second-team All-AFC by UPI in 1986 and 1987 and was voted Second-team All-Pro by NEA in 1989. Smith played his entire 10-year NFL career with the Chargers. His top sack season was 1986, when he totalled 11 sacks. In 2009, Smith was voted by fans and the Chargers Hall of Fame as one of the 50 greatest Chargers of all time.
Billy Ray Smith Jr was the co-host of the U-T TV morning show with Scott Kaplan and Amber Mesker. Weekdays 6AM to 11AM. However, he left the show in December 2012 when he and co-host Scott Kaplan were re-hired at XX Sports Radio (1090 AM)for the 3pm-6pm slot.