Pete Alonso delivered an emotional farewell to Mets fans on Thursday, leaving a lasting impression on the franchise that was his home for his entire MLB career until recently signing with the Orioles.

In a touching Instagram post, Alonso expressed his gratitude to the fans who supported him over his seven seasons with the Mets. “New York, thank you,” he began. “These past years have profoundly shaped my life. This city demands excellence, and I’m proud to say I gave my all to earn the honor of wearing that jersey.”

He went on to acknowledge the invaluable support he received from the Mets’ coaching staff and his teammates over the years. “I’ve been fortunate to be surrounded by amazing teammates, coaches, trainers, and staff, who have all contributed to making me the player and person I am today,” Alonso shared. “I’m eternally grateful for everyone who challenged, supported, and believed in me throughout this journey.”

Alonso also paid tribute to the passionate fanbase, saying, “Thank you for your passion and love, even the tough love that comes with playing in New York. Your energy was electric from the first pitch and made the stadium come alive every time I stepped up to bat. Your belief in me pushed me to be better.”

“I’ve been blessed with incredible teammates, coaches, trainers, staff, and countless people who helped shape me into the player and man I am today,” he continued. “I’m forever grateful for every person who challenged me, supported me and believed in me along the way.

“Thank you for the passion. Thank you for the love. Even the tough love that comes with playing for New York. When it came time for first pitch, thank you for being electric through it all. Thank you for getting rowdy every time I stepped up to the plate and made the building shake when the ball found a seat over the wall. Your energy fueled me more than you’ll ever know. You believed in me, and you made me better.”

Alonso signed a five-year deal worth $155 million with Baltimore, with it later being revealed that the Mets did not even make a formal offer to the first baseman.

The five-time All-Star is coming off a season where he posted a slash line of .272/.347/.524 with a NL-leading 41 doubles and 38 home runs, earning him the first Silver Slugger of his career.

Alonso’s deal came just a day after Edwin Diaz bolted to the Dodgers for a three-year, $69 million contract with the reigning World Series champs.

After losing franchise staples in Alonso and Diaz, Mets owner Steve Cohen had a sympathetic and optimistic message for the fans.

“I totally understand the fans’ reaction,” Cohen texted The Post’s Jon Heyman on Wednesday. “There is lots of offseason left to put a playoff team on the field.”