Christian Ulmen was born in Neuwied/Rhein on September 22nd, 1975, but grew up in Hamburg where he created features for Radio Hamburg and OK-Radio from a teenage age on. In 1994, Ulmen became a presenter for "Disney & Co.", a children"s TV Show for RTL. Then, in 1996, he started to present different programmes for the music channel MTV and later on starred in his own productions like "Unter Ulmen" and "Ulmens Auftrag". In January 2005, Pro 7 aired Ulmen"s reality TV show "Mein neuer Freund".

In 2003, Ulmen debuted on the big screen in Benjamin Quabeck"s "Verschwende deine Jugend" (Play It Loud!). He then played the leading part in Leander Haußmann"s adaptation of the Berlin novel "Herr Lehmann" (Berlin Blues) and received the Bavarian Movie Award for Best Leading Actor. In 2005, Ulmen, together with Alexandra Maria Lara, starred in Doris Dörrie"s romantic comedy "Der Fischer und seine Frau" (The Fisherman and His Wife).

Ulmen was praised by critics for his performance in a supporting role in Oskar Roehler"s film "Elementarteilchen" ("Elementary Particles"), an adaptation of Michel Houellebecq"s novel, and for his leading role in Ute Wieland"s women’s football comedy "FC Venus – Elf Paare müsst ihr sein" (FC Venus – Women with Balls").

For his portrayal of a police psychiatrist in the comedy series "Dr. Psycho", he received a Bayerischer Filmpreis and a Grimme Award. In 2009, Ulmen starred in "Maria, ihm schmeckt"s nicht", an adaptation of Jan Weiler"s eponymous novel, and the comedy "Männerherzen". In 2010, he played alongside Christian Tramitz in "Jerry Cotton", took the lead in Lars Jessen"s culture clash comedy "Hochzeitspolka" and starred in Harald Sicheritz" satire "3faltig" and Till Endemann"s comedy "Vater Morgana".