Jacobs made his NFL debut in Week 1 against the Denver Broncos on Monday Night Football. In the game, Jacobs rushed 23 times for 85 yards and two touchdowns and caught one pass for 28 yards in the 24-16 victory. In the next game against the Kansas City Chiefs, he rushed 12 times for 99 yards as the Raiders lost by a score of 28-10. Three weeks later against the Chicago Bears at Tottenham Hotspur Stadium, Jacobs rushed 26 times for 123 yards and two touchdowns and caught three passes for 20 yards in the 24-21 win. During Week 7 against the Green Bay Packers, he rushed 21 times for 124 yards in the 42-24 road loss. Two weeks later against the Detroit Lions, Jacobs rushed 28 times for 120 yards and two touchdowns in the 31–24 victory. After just the eighth game of the season, Jacobs set the Raiders rookie record for rushing yards in a season with 740, surpassing Marcus Allen's old record of 697. In the next game against the Los Angeles Chargers on Thursday Night Football, Jacobs rushed for 71 yards and the game-winning touchdown and caught five passes for 30 yards. In Week 11 against the Cincinnati Bengals, Jacobs rushed 23 times for 112 yards in the 17–10 win. In Week 13 against the Kansas City Chiefs, Jacobs rushed 17 times for 104 yards in the 40–9 loss. During the game, Jacobs became the first running back in Raiders' history to rush for 1,000 yards in a rookie season. Jacobs missed three of the last four games of the season due to a shoulder injury and skin infection. Jacobs finished the 2019 season with 1,150 rushing yards and seven rushing touchdowns.