Entering the 2018 season, Torres was labeled as the fifth-best prospect in baseball and the best shortstop prospect by MLB.com. During spring training, Torres competed with Miguel Andujar and other infielders for a spot on the opening day roster. On March 13, 2018, Torres was optioned to Scranton/Wilkes-Barre to begin the year. He was pulled out of the game on April 22 after six innings. Torres misunderstood thinking it was a punishment for not hustling enough but after the game he was called into manager Bobby Mitchell's office where he heard of his promotion to the Major Leagues.
Torres made his MLB debut on April 22, 2018, as the second-baseman against the Toronto Blue Jays, going 0 for 4. The next day, against the Minnesota Twins, Torres recorded his first MLB hit. On May 4, Torres hit his first career home run, off Josh Tomlin, which at the age of 21 was the youngest Yankee to homer since John Ellis in 1969. Two days later, against the Cleveland Indians, Torres hit his first career walk-off, a home run off of relief pitcher Dan Otero, becoming the youngest Yankee to hit a walk-off homer and giving the Yankees a 7–4 victory. On May 21, against the Texas Rangers, Torres recorded his first multi-homer game when he hit two home runs as the Yankees won 10–5. On May 25 against the Los Angeles Angels, Torres hit a home run in his fourth straight game; at 21 years and 163 days old, he became the youngest player in American League history to accomplish that feat. Torres was named AL Player of the Week for the week ending on May 27, when he hit .368/.429/1.158 with five home runs and nine RBIs. On May 29, Torres hit a walk-off single to beat the Houston Astros in extra innings. Torres was also named American League Rookie of the Month for May. He slashed of .317/.374/.659 scoring 13 runs, 26 hits, nine home runs and 24 RBI.