Klaassen was born on February 21, 1993, in Hilversum. He followed the youth academy in Amsterdam and made his debut on November 22, 2011, in the UEFA Champions League match against Olympique Lyon (0–0). After the 2016/2017 season, he moved to the English club Everton. Between 2018 and 2020, the midfielder played for Werder Bremen before returning to Ajax. In the summer of 2023, he moved to Italy, where the 32-year-old became Serie A champion with Internazionale. Early last season, he returned once again and rejoined the first-team squad during pre-season.
Klaassen has now played 356 official matches for Ajax's first team, scoring 101 goals and providing 52 assists. He won the Dutch league title with Ajax five times (2012, 2013, 2014, 2021, and 2022). In addition, he lifted the Johan Cruijff Shield in 2013 and the Dutch Cup in 2021. In 2016, the former international was named Dutch Footballer of the Year.
Technical director Alex Kroes: "It's great that we can keep Davy at the club for longer. He's in top shape and, with his tremendous drive, he can lead the team at moments when that extra push is needed. He has a knack for scoring and is a prime example of a real Ajax player with football intelligence. In short, with all his experience, he is a crucial part of this squad, both on and off the pitch."
