Pete Alonso

Alonso met Haley Walsh in the summer of 2015 while playing collegiate summer baseball in the Cape Cod Baseball League. The couple maintained a long-distance relationship while Alonso attended the University of Florida and Walsh studied at Michigan State University. They became engaged in November 2018 and married on November 12, 2021, at Sacred Heart Catholic Church in Tampa, Florida. In October 2025, they welcomed their first child, a son.

In 2020, Alonso and his wife founded The Alonso Foundation, a charitable organisation supporting youth sports, veterans, and animal welfare causes. Through the foundation, they launched initiatives such as Homers For Heroes, supported animal rescue efforts by pledging donations for home runs, and hosted youth baseball events including the Battle for the Bay at Plant High School. In March 2022, Alonso survived a severe car accident in Tampa when another driver ran a red light and struck his vehicle, causing it to flip three times; he emerged without injury.

Peter Morgan Alonso was born in Tampa, Florida, to Michelle Lynn Alonso and Peter Matthew Alonso. His paternal grandfather, Peter Conrad Alonso, was a Spanish refugee who left Barcelona during the Spanish Civil War, arrived in New York through Ellis Island, and settled in Queens. Alonso played youth baseball in Tampa, including a stint on a Little League team that earned him a congratulatory letter from New York Yankees manager Joe Torre in 2002.

Alonso attended Jesuit High School in Tampa for two years before transferring to Henry B. Plant High School, where he focused exclusively on baseball after also playing lacrosse and football as a freshman. After graduating in 2013, he enrolled at the University of Florida to play for the Florida Gators. He earned All-Southeastern Conference honors as a freshman, competed in the 2015 and 2016 College World Series, and developed his hitting profile during summer stints with the Madison Mallards and the Bourne Braves.

The New York Mets selected Alonso in the second round of the 2016 MLB draft. After advancing through the minor league system and winning the Joe Bauman Home Run Award in 2018, he earned a spot on the Mets' 2019 Opening Day roster. Alonso produced an extraordinary rookie campaign, hitting 53 home runs to lead the majors and surpass Aaron Judge's MLB rookie record. That season, he won the 2019 MLB Home Run Derby, was named to the All-MLB First Team, and received 29 of 30 first-place votes to win the National League Rookie of the Year Award.

Alonso established himself as a central power hitter in New York, winning his second consecutive Home Run Derby in 2021 and leading the National League with 131 RBIs in 2022. During the 2024 postseason, he hit a decisive ninth-inning, three-run home run against the Milwaukee Brewers in Game 3 of the National League Wild Card Series, becoming the first player in MLB history to hit a go-ahead home run while trailing in the ninth inning or later of a winner-take-all playoff game. In August 2025, he hit his 253rd home run with the Mets, surpassing Darryl Strawberry to become the franchise's all-time home run leader.

Following the 2025 season, in which he won a Silver Slugger Award and played in all 162 regular-season games, Alonso opted out of his contract to enter free agency. In December 2025, he signed a five-year, $155 million contract with the Baltimore Orioles. Upon joining the team, he chose uniform number 25, citing the birth year of his son.