Ryan is of Spanish/American descent, the oldest son of actor/director Michael De Mesa and actress/director Gina Alajar. Oldest brother of actors Geoff Eigenmann and A.J. Eigenmann and First cousin of TV host Gabby Eigenmann., Scion (a third generation) of the legendary Gil-Eigenmann clan of actors. Grandparents are Eddie Mesa and Rosemarie Gil.ephew of Filipino actors Mark Gil and Cherie Gil. Ryan is under the management of Viva Entertainment.

Independent Short/ Full Length Film Credits (2007):
Baliw (2007), Doble Vista (2007)

Previous Years Independent Short/ Full Length Film Credits:
Anak ng tinapa (2005), Big Time (2005), Pinoy/Blonde (2005), Co-ed Scandal (2006)

Mainstream Film Credits:
I'm Sorry, My Love (1998), Gangland (1998), Jose Rizal (1998), Sumigaw ka hanggang gusto mo (1999), Ekis: Walang tatakas (1999), Unfaithful Wife 2: Sana'y huwag akong maligaw (1999), Asin at paminta (1999), Lastikman (2003), Keka (2003), First Time (2003/II), Milan (2004), Kulimlim (2004), The Great Raid (2005), The Promise (2007), Hide and Seek (2007)

T.V. Series:
"Growing Up" (1997),"Pintados" (1999), "Te amo, maging sino ka man" (2004), "Mga Anghel na walang langit" (2005), "Etheria: Ang ikalimang kaharian ng encantadia" (2005), "Captain Barbell" (2006), "Maging sino ka man" (2006), "Kokey" (2007)