Didrik Slagheck (died 24 January 1522) was a Danish archbishop, military commander during the Swedish War of Liberation, and often pointed out as an active participant in the Stockholm Bloodbath.

[3] Slagheck was the illegitimate son of a Westphalian[4] priest and appears to have been working in the papal office during his early life.

He became one of the three Danish leaders left behind to govern Sweden when Christian II returned to Denmark, soon making himself unpopular among the population.

Slagheck participated as a military commander during the early stages of the rebellion led by Gustav Vasa, leading the Danish forces during the Battle of Västerås.

He would not keep this position for long, as Pope Leo X had been greatly discontented when he received word of the execution of two bishops in the Stockholm Bloodbath, prompting Christian II to put the entire blame on Slagheck.