Lasse Nielsen

• Lasse Nielsen (footballer, born 1987), Danish footballer who plays for Lyngby BK
• Lasse Nielsen (footballer, born 1988), Danish footballer who plays for Göztepe
• Lasse Nielsen (canoeist), Danish sprint canoeist
• Lasse Nielsen (filmmaker), Danish filmmaker, co-writer and co-director of Leave Us Alone and ''You Are Not Alone''