Career
He started as youth coach at Ikast fS and continued in this job, when the club merged with Herning Fremad to form Football Club Midtjylland. In 2006 he replaced Hans Brun Larsen as the manager of the Danish national under-17 football team After two years in this job he returned to Midtjylland to become assistant manager.
When Allan Kuhn resigned on 15 April 2011, Riddersholm was promoted to the position as head coach.
Riddersholm led the club to its first Danish championship in the 2014-2015 Danish Superliga, but shortly after he resigned as manager of the club On 6 December 2015 he was named successor of Morten Wieghorst as manager of AGF. As of 6 December 2015 Managerial = Football Club Midtjylland.