Brown chose Notre Dame and played there from 1984-1987, earning the nickname "Touchdown Timmy." In his first year, he set a freshman record with 28 receptions. As a junior, he set a record with 1,937 all-purpose yards. He made the College Football All-America Team twice and won the Heisman Trophy in 1987, becoming the first wide receiver ever to win the award. His alma mater, Woodrow Wilson High School, became the first high school in history to produce more than one Heisman winner; as of 2007, Woodrow is still the only public high school with two winners, though private school Mater Dei has matched the record. During that year, he caught 34 passes for 846 yards, returned 34 punts for 401 yards, rushed for 144 yards, and gained 456 yards on 23 kickoff returns. He also scored eight touchdowns. Brown finished his career at Notre Dame with 137 receptions, a school record 5,024 all-purpose yards, and 22 touchdowns.
However, just as in high school, Brown's team achieved limited success, with a 25-21 record over his four seasons, and an 0-2 record in bowl games. Ironically, in the year after Brown graduated (1988), Notre Dame won the national title.
Brown was released by the Raiders before the 2004 season, as he did not want to accept a smaller role in the offense. He was signed shortly thereafter by the Buccaneers (coached by former Raider head coach Jon Gruden). The move was mildly controversial. Brown had always been a fan favorite in the Oakland area and was much admired by many current and former Raiders players and staff over the 15 years he spent with the Raider organization. However, Brown's declining performance in recent years may have contributed to the decision to release him. He was the last of the Los Angeles Raiders to remain with Oakland.
On September 27, 2004, in his first game at Oakland since being signed by Tampa Bay, Brown reached 100 career receiving touchdowns, tying him (with Steve Largent) for 3rd on the NFL's all-time career receiving touchdown list (behind former teammate Jerry Rice [204] and Cris Carter [130]).
In 2005, Brown signed a one-day contract with the Raiders to retire with the team he had played 16 seasons for. The July 18 news conference was attended by two Raiders' officials, and only one active Raider, wide receiver Jerry Porter. Brown retired with 14,934 receiving yards, the second-highest total in NFL history, 1,094 receptions (3rd), and 100 touchdown catches (3rd-Tied). Brown also gained 190 rushing yards, 3,320 punt-return yards, 3 fumble-return yards, and 1,235 yards returning kickoffs. This gave him a total of 19,682 combined net yards, ranking him #5 among the NFL's all-time leaders in that category at the time of his retirement. He also scored 105 total touchdowns (100 receiving, 1 rushing, 3 punt returns, 1 kickoff return).