Gallup moved on to Butler Community College to improve his grades. As a freshman in 2014, he led the team with 780 receiving yards and 11 touchdowns. Against Dodge City Community College, he tallied 5 receptions for 287 yards and three touchdowns. In 2015, Gallup played in only three games due to an ankle injury and had 9 receptions for 74 yards and a touchdown. In 2016, Gallup transferred to Colorado State University. He started slow in his first season, but began to increase his production after his third game against the University of Northern Colorado, when he had 4 receptions for 82 yards and one touchdown. He played in all 13 games, recording 76 receptions for 1,272 yards and 14 touchdowns. As a senior in 2017, Gallup was a finalist for the Fred Biletnikoff Award. He started all 13 games, posting 100 receptions for 1,413 yards and seven touchdowns. Gallup finished his career with various accomplishments. He had 3 of the top 8 single-game all-time receiving performances in school history, 4 of the top 10 games in school history for receptions, ranked second in single-season receiving touchdowns, only player in school history to catch 3 or more touchdowns three times, record for single-season receptions, second-best single-season receiving yards, ranked fifth in career receptions.
College statistics
Professional career
On November 20, 2017, it was announced that Gallup had accepted his invitation to play in the Senior Bowl. On January 27, 2018, Gallup caught three passes for 60-yards and was part of Denver Broncos'head coachVance Joseph's North team that lost 45-16 to the South coach by Houston Texans' head coach Bill O'Brien. He attended the NFL Scouting Combine in Indianapolis and completed all of the combine and positional drills. On March 7, 2018, Gallup participated at Colorado State's pro day and performed the 40-yard dash, 20-yard dash, 10-yard dash, broad jump, short shuttle, and three-cone drill. At the conclusion of the pre-draft process, Gallup was projected to be a third round pick by NFL draft experts and scouts. He was ranked as the 10th best wide receiver prospect in the draft by DraftScout.com and was ranked the 14th best wide receiver by Scouts Inc. The Dallas Cowboys selected Gallup in the third round in the 2018 NFL Draft. Gallup was the ninth wide receiver drafted in 2018. On May 21, 2018, the Dallas Cowboys signed Gallup to a four-year, $3.52 million contract that includes a signing bonus of $889,980.
2018 season: Rookie year
Gallup made his NFL debut in the season-opening 16-8 loss to the Carolina Panthers, catching one pass for nine yards. On October 21, he caught his first NFL touchdown on a 49-yard pass from Dak Prescott in a 20-17 loss to the Washington Redskins. Gallup finished his rookie year with 33 receptions for 507 yards and two touchdowns.
2019 season
During the season-opener against the New York Giants, Gallup caught seven passes for 158 yards in the 35–17 victory. He missed Weeks 3-4 due to a knee surgery. During Week 11 against the Detroit Lions, Gallup finished with nine receptions for 148 yards in the 35–27 road victory. Three weeks later against the Chicago Bears on Thursday Night Football, he caught six passes for 109 yards and a touchdown in the 31–24 road loss. In the regular-season finale against the Washington Redskins, he caught five passes for 98 yards and three touchdowns in the 47–16 victory. Overall, Gallup finished the 2019 season with 66 receptions for 1,107 receiving yards and six receiving touchdowns.
