Troels Nielsen (born 1982) better known by his stage name Troo.L.S is a Danish musician and music producer from Albertslund, Copenhagen, Denmark.

His career debut was in the local Danish hip hop group Sidste Niveau. He also contributed to the group Suspekt and their self-titled album Suspekt in 1999. He later joined Suspekt, where he wrote, co-composed and also featured as a rapper on "Ingen Slukker The Stars" in 2003 and "Prima Nocte" in 2007.

In the 2005, an album called "Forklædt Som Voksen", a joint venture with Danish rapper Orgi-E, was released.

Troo.L.S' musical collaborations include Danish artists such as: L.O.C., U$O, Drengene Fra Angora and Anders Matthesen.

With Rune Rask, he co-wrote and composed the song "Gangsta Bop" that appears on Akon's album Konvicted.

For which the two received a Grammy Nomination.

In late 2007, he left Suspekt and subsequently signed to Akon's label Konvict and relocated to Atlanta, GA.

His productions feature artists such as Snoop Dogg, The Game and Tech N9ne.