Peter Morgan Alonso (born December 7, 1994), nicknamed "Polar Bear", is an American professional baseball first baseman for the Baltimore Orioles of Major League Baseball (MLB). He has previously played in MLB for the New York Mets. Internationally, Alonso represents the United States.
Alonso played college baseball for the Florida Gators before the Mets selected him in the 2016 MLB draft. He made his MLB debut on Opening Day in 2019 and won the National League Rookie of the Year Award that year, setting a major league record for rookies with 53 home runs. Alonso is a five-time MLB All-Star who led the league in home runs in 2019 and in runs batted in in 2022, and is the Mets' all-time franchise leader in home runs. He has also won the MLB Home Run Derby twice, in 2019 and 2021.
Peter Morgan Alonso was born on December 7, 1994, in Tampa, Florida. Alonso attended Jesuit High School in Tampa for his first two years of high school, and transferred to Henry B. Plant High School in Tampa to finish high school. He played lacrosse and football as a freshman before deciding to focus solely on baseball. For the baseball team, he was a third baseman.
His grandfather, Peter Conrad Alonso, was a Spanish refugee who fled Barcelona during the Spanish Civil War to New York City through Ellis Island. He settled in Queens and became a Brooklyn Dodgers fan. He attended Jamaica High School but his education was cut short due to his military service in World War II from 1942 to 1945 but continued his education at New York University earning multiple degrees, where he met Anna (née Pirraglia, of Italian descent) whom he married in 1951. They then moved to Long Island, begetting three daughters and Peter Matthew, Pete Alonso's father, before resettling the family to Lancaster, Ohio in 1963. Later, his father met and married his mother, Michelle Lynn Alonso (née Morgan), an Ohio native who was a student-athlete at Ohio Wesleyan University having played college softball.
Alonso enrolled at the University of Florida, where he played college baseball for the Florida Gators as a first baseman. He was named All-Southeastern Conference in his freshman year. In 2014, he played collegiate summer baseball with the Madison Mallards of the Northwoods League, and he was inducted into their Hall of Fame in 2024. In the summer of 2015, he played for the Bourne Braves of the Cape Cod Baseball League. In 2016, his junior year, he hit .374/.469/.659 with 14 home runs and 60 RBIs in 58 games. He competed for Florida in the 2015 and 2016 College World Series.
The New York Mets selected Alonso in the second round of the 2016 Major League Baseball draft with the 64th overall pick. He signed with the Mets for a $909,200 signing bonus, and made his professional debut in 2016 with the Brooklyn Cyclones of the Class A Short Season New York–Penn League. He posted a .322 batting average with 5 home runs and 21 RBIs in 30 games and was chosen to participate in the league's All-Star Game. He began the 2017 season with the St. Lucie Mets of the Class A-Advanced Florida State League, and after batting .286 with 16 home runs and 58 RBIs in 82 games, was promoted to the Binghamton Rumble Ponies of the Class AA Eastern League in August, where he batted .311 with 2 home runs and 5 RBIs in 11 games.
MLB.com ranked Alonso as New York's fourth-best prospect going into the 2018 season. He began the season in Binghamton, and received a midseason promotion to the Las Vegas 51s of the Class AAA Pacific Coast League. He represented the Mets in the 2018 All-Star Futures Game. In 132 games between Binghamton and Las Vegas, he slashed .285/.395/.579 with 36 home runs and 119 RBIs. He won the Joe Bauman Home Run Award. That season, Alonso was the final batter in Cashman Field history, as he hit a walk-off home run in the bottom of the 9th inning during the last baseball game played at the facility.
Alonso made the Mets Opening Day roster in 2019 as the starting first baseman. He was in the team's starting lineup on Opening Day on March 28, and recorded his first major league hit against Washington Nationals pitcher Justin Miller in the 8th inning. On April 1, Alonso hit his first major league home run, off of Drew Steckenrider of the Miami Marlins leading the Mets to a 7–3 victory. On April 9, he had his first career multi-home run game against the Minnesota Twins in a Mets 14–8 loss.
Alonso became the first player in MLB history since 1900 with 11 extra-base hits in his first 10 career games. No other player ever had more than nine. In April, he batted .292 with 9 home runs, 8 doubles, one triple and 26 RBIs in his first games in the big leagues. With his performance, Alonso won the National League Rookie of the Month Award for April. His nine home runs led all MLB rookies and are tied for the most by a Mets player before May 1 with Neil Walker (2016), John Buck (2013), Carlos Delgado (2006), and Dave Kingman (1976).
On June 22, Alonso hit his 26th home run, breaking the National League record for most home runs by a rookie before the All-Star break, passing Cody Bellinger. The next day, with his 27th home run, he broke the Mets rookie home run record, previously set by Darryl Strawberry in 1983. On June 30, Alonso was selected as a reserve to the 2019 MLB All-Star Game. He also won the NL Rookie of the Month Award for the month of June.
On July 7, Alonso became the second player in Mets history to hit the most home runs (30) before the All-Star break, after Dave Kingman (1976). On July 8, Alonso won the 2019 Home Run Derby, defeating Toronto Blue Jays first baseman Vladimir Guerrero Jr. 23–22 in the final round, becoming only the second rookie after Aaron Judge to win the Derby outright. On the way to the final round, Alonso also beat Carlos Santana and Ronald Acuña Jr., hitting 57 total home runs during the entire Derby.
On August 15, Alonso hit his 39th home run, tying Cody Bellinger for the most home runs by a rookie in National League history. Alonso finished the game with a career-high 5 hits and 6 RBIs. He broke Bellinger's record on August 18 with his 40th home run in an 11–5 win against the Kansas City Royals. On August 27, Alonso hit his 42nd home run to become the Mets all-time single-season home run leader, surpassing Carlos Beltrán and Todd Hundley. He is the first rookie to set his franchise's single-season home run record since Johnny Rizzo did it for the Pittsburgh Pirates in 1938.
On September 27, Alonso hit his 52nd home run of the season, tying Aaron Judge for the most home runs by a rookie in MLB history. He hit his 53rd the next day off of Atlanta Braves pitcher Mike Foltynewicz to break Judge's record. In his rookie season, Alonso played in 161 games, batting .260/.358/.583 with 53 home runs and 120 RBI. His 53 homers led all of MLB for the 2019 season. After the season on November 11, Alonso was awarded the National League Rookie of the Year, receiving 29 of 30 first-place votes. On December 10, he was named to the first team of the inaugural All-MLB Team.
On September 3, 2020, Alonso hit his first career walk-off home run in a 9–7 victory against the New York Yankees. His sophomore season was a step back from his breakout rookie year; Danny Abriano of Yahoo Sports called it "a season to forget." However, he had the highest maximum exit velocity of all major league hitters, at 118.4 miles per hour (190.5 km/h). In the 2020 season shortened by COVID-19, Alonso played in 57 games and batted .231/.326/.490 with 16 home runs and 35 RBIs.
Alonso's sophomore slump coupled with a second consecutive breakout season from Dominic Smith led some talent evaluators to favor the latter as the team's starting first baseman heading into the 2021 season.
On July 12, Alonso won his second straight Home Run Derby after defeating Baltimore Orioles first baseman Trey Mancini 23–22 in the final round. He became the third player ever to win back-to-back Derbies, as well as the fourth player to win two Derbies (after Ken Griffey Jr., Prince Fielder, and Yoenis Céspedes). Newsday Mets beat writer Tim Healey noted Alonso has earned $2 million from winning the Derby twice while making $1.47 million from 2019–2021 in base salary while playing for the Mets.