Haller finished 2021/22 on an Eredivisie-leading 21 goals, and ended up third in the UEFA Champions League charts behind Karim Benzema (15) and Robert Lewandowski (13) after scoring 11 times during Ajax's run to the round of 16. The 28-year-old striker returns for a second stint in Germany following a 33-goal spell with Eintracht Frankfurt between 2017 and 2019.
"I can't wait to feel the support of 80,000 fans in the stadium as part of the BVB family," Haller said in a club statement. "Hopefully over the coming years we'll achieve big things together, and then celebrate them together." Haller scored goals in France with Auxerre and the Netherlands with Utrecht, before joining Niko Kovac's Frankfurt in summer 2017. The former France youth international produced a nine-goal debut campaign in the Bundesliga and lifted the DFB Cup, before helping form one of the Bundesliga's deadliest attacks in 2018/19, alongside Ante Rebic and Luka Jovic. He scored 15 times as Frankfurt narrowly missed out on a top-four finish domestically, and added a further five goals to his tally as the Eagles reached the UEFA Europa League semi-finals.
Haller spent a season-and-a-half in England at West Ham, scoring 10 goals in 48 English Premier League appearances, before returning to the Netherlands with Ajax in January 2021. A domestic double winner at the end of his first campaign at the club, the 12-time Cote d'Ivoire interntional got his hands on a second successive Eredivisie title in 2021/22. All told, he registered 47 goals and 16 assists in 65 competitive appearances for the record Dutch champions. We're very pleased that in Sebastien Haller we've been able to sign a proven centre forward who recently made waves in the Champions League, but who also knows the Bundesliga and has already demonstrated his class and top-quality finishing ability in the league," said Dortmund sporting director Sebastian Kehl.
"The package as a whole is very promising. Sebastien has a great physical presence and is very resilient. With his experience, he can help our youngsters in attack and provide stability. In the conversations we had he made it clear that he wants to achieve big things with BVB."