Nathan Fillion (born March 27, 1971, height 6' 1½" (1,87 m)) is a Canadian actor, currently starring as Richard Castle on the ABC series Castle. He is also known for his portrayal of the lead role of Captain Malcolm Reynolds in the television series Firefly and its film continuation Serenity, and to a lesser extent for his regular role as Johnny Donnelly on the sitcom Two Guys and a Girl.
Fillion has been involved in TV soap operas like One Life to Live, traditionally distributed films like Slither and Trucker, Internet-distributed films like Dr. Horrible's Sing-Along Blog, voice-over work like the video games Halo 3: ODST and Halo: Reach, and the theatre. He has also been recognized for his looks in People and Entertainment Weekly.
Fillion's public service work includes the co-founding of Kids Need to Read, an organization dedicated to getting more books into underfunded libraries.