Jan Hojer (born February 9, 1992) is a German professional rock climber. He is known for winning one World Cup and two European Championships in bouldering. On May 2010, he climbed Action Directe, still considered to be one of the most difficult routes in the world. From 2013 to 2015, he solved several 8C (V15) boulder problems.
Hojer started participating in German Lead climbing youth competitions in 2004, at the age of 10. From 2008 to 2010 he participated in the Lead Climbing World Cup. Since his performances in lead climbing were never outstanding, he quit competing in that discipline in 2011 and started competing in bouldering. Notable results started coming next year, when he ranked fifth in the Climbing World Championships. He won the seasonal title of the Bouldering Climbing World Cup in 2014 and finished second in 2015.
In 2015 and 2017 he won the Climbing European Championships in Bouldering. Also in 2017, he won the silver medal at the Bouldering World Games in Wroclaw, Poland.