Martin Ørnskov Nielsen (born 10 October 1985) is a Danish professional footballer who plays for Danish Superliga club Lyngby BK where he is currently captain.
Ørnskov began playing football at age 5 in the Silkeborg IF academy and came through the ranks to make well over 100 appearances in all competitions for them.
He moved to Norwegian side Viking in 2012, where he had a short spell before moving back to Denmark to join Brøndby IF in 2013.
After three years in Brøndby, Ørnskov signed with Lyngby BK in 2016, experiencing both European football, relegation and promotion in three years.