Andrew Benintendi attended Madeira High School in Madeira, Ohio. As a senior, he batted .564 with 12 home runs, 57 RBIs, and 38 stolen bases for the Mustangs baseball team, and was the ABCA/Rawlings National High School Player of the Year and Ohio Gatorade Baseball Player of the Year. He finished his high school career with an Ohio-record 199 career runs scored. He also played high school basketball, earning 2011-12 Cincinnati Enquirer Division III Co-Player of the Year honors and setting school records in career points (1,753) and season points (638), career 3-pointers (180), and points per game in a season (25.5). He was drafted by the Cincinnati Reds in the 31st round of the 2013 Major League Baseball draft, but he did not sign.

He enrolled at the University of Arkansas to play college baseball for the Arkansas Razorbacks baseball team. As a true freshman, he played in 61 games, with 60 starts and hit .276/.368/.333 with one home run and 27 RBI.

In 2015, Andrew led the Southeastern Conference in batting average (.380), home runs (19), on-base percentage (.489), slugging percentage (.715), and walks (47). He was named the SEC Player of the Year. He also won the Baseball America College Player of the Year Award, the Dick Howser Trophy, and the Golden Spikes Award. He was considered one of the top prospects for the 2015 Major League Baseball draft.

Andrew was drafted by the Boston Red Sox with the seventh overall selection in the 2015 Major League Baseball draft. He signed with the Red Sox, receiving a $3.6 million signing bonus. He made his professional debut with the Lowell Spinners of the Class A-Short Season New York–Penn League. Andrew finished the 2015 season playing 19 games for the Class A Greenville Drive going 26/74 (.351) and posting an ops of 1.011. He began the 2016 season with the Salem Red Sox of the Class A-Advanced Carolina League, and received a promotion to the Portland Sea Dogs of the Class AA Eastern League on May 15th.

The Red Sox promoted him to the major leagues on August 2nd straight from Double-A, only 421 days after being selected in the draft. He made his major league debut on August 2nd against the Seattle Mariners as a pinch hitter and recorded his first major league hit off of Hisashi Iwakuma on August 3rd. He recorded both his first major league triple and home run against the Detroit Tigers on August 21st in a 10-5 loss.

On October 6th, in Game 1 of the 2016 American League Division Series against the Cleveland Indians, he hit a home run in his first postseason at-bat off Indians' pitcher Trevor Bauer. With the feat, he became the youngest Red Sox player to hit a home run in a postseason game. However, the Indians won the game by a score of 5-4 and the series 3-0. He ended the 2016 season with a .295 batting average, 31 hits, 14 RBI, two home runs, and one stolen base.

There weren’t a lot of bright spots on the Red Sox offense in 2017, and for a guy in his first full season, it was a really solid year for Andrew. Most impressive about him was his approach at the plate. The lefty had incredible discipline for someone with his low experience level, and he utilized his understanding of the strike zone to make plenty of contact while also drawing walks at an above-average rate.

Andrew had some really bad stretches in 2017, and they put a damper on his overall line at the end of the year, but he always managed to hit his way out of it. He was also at his best when runners were on base in 2017. That was something of a theme for the offense as a whole, who managed to score enough to win games despite unimpressive overall production. The rookie posted an OPS of just .697 with the bases empty this year, but upped that mark to .874 with runners on and to .960 with runners in scoring position.

His strengths weren’t limited to the batter's’ box, either. He wasn’t perfect on the bases, but. he was a very good base stealer, though, swiping 20 bags in 25 tries. Additionally, he provided strong defense in left field and became more and more comfortable with the Monster as the year went on.

For the 2018 Red Sox, Andrew was again on the Opening Day roster. Through the first half of the season, he was the team's regular left fielder, usually batting second, behind Mookie Betts.

Andrew Andrew quietly pieced together a very good 2018 campaign. In just his second full season with the Boston Red Sox, Andrew was one of the best two-way outfielders in the American League. He finished the regular season with a .290 average, 16 home runs, and 87 RBIs. His 6 triples also led the team. He hit 15 more doubles and scored 19 more runs in 2018. He also crossed the 20-stolen base mark for the second year in a row, swiping 21 of 24 bases. Perhaps his biggest moment of the regular season came on August 5th, when his walk-off single sealed a four-game sweep of the Yankees.

Not only did he produce offensively, Andrew was also one of the best defensive outfielders in the American League. He finished second in 2018 Gold Glove Awards, to Alex Gordon. His 11 assists were tied for the most by a left fielder in Major League Baseball.

His signature moment came in the ninth inning of ALCS Game #4, with the Red Sox leading the Astros 8-6. With two outs, Alex Bregman ripped a sinking line drive to left field. On a do-or-die attempt, Andrew made an incredible diving catch to rob Bregman of what might have been a game-winning extra base hit. The catch gave the Red Sox a comfortable 3-1 series lead.

In 2019, Andrew took a giant step back. His struggles extended back to 2018 when his power short-circuited. He flipped up to the leadoff spot and then flopped. He hit .266 with 13 homers and 68 RBIs, in a time when 30 homers is the bar.

In 2020, the Sox signed him to a two-year $10 million dollar deal, but he was injured late in the season after recording his 500th hit. On February 10, 2021 he was traded to the Kansas City Royals.