Actor, singer, model, and dancer Rainier Castillo, was born Rainier Joseph Diaz Castillo on October 21, 1985 in Quezon City, Philippines. He was known for his “killer smile” and a hairstyle like that of F4 member Jerry Yan. Rainier joined the reality-based artista search “Starstruck” of GMA Network when he was a freshman at AMA Computer College. During the competition, he was linked to the four female survivors of the said search namely Yasmien Kurdi, Jennylyn Mercado, Jade Lopez (who had a crush on him), and Sheena Halili, whom he had a relationship after the search. Rainier made it to the Final Four in the First Season of Starstruck but did not have the chance to grab the title of Ultimate Starstruck Male Survivor and lost it to Mark Herras.
Though he lost in the said competition, joining Startstruck was the best thing that ever happened to Rainier. It opened doors for even bigger opportunities for him and made him appear in different shows of GMA Network such as the teen-oriented shows Joyride and Click. He even appeared in fantaseryes Majika, Mulawin, Kamandag, Fantastic Man, and Tasya Fantasya. He also made himself visible to comedy shows like Hokus Pokus and drama series Love to Love, Bakekang, and Maynila. He was also exclusively paired to Yasmien Kurdi in different shows and movies.
Rainier Castillo left GMA Network and transferred to TV5, where he signed a two-year non-exclusive contract. He is also under a new manager in the person of Noel Ferrer, who also manages Ryan Agoncillo. He joined the funny cast ofLokoMoKoU which stars Tuesday Vargas, Empoy, JC de Veyra, Caloy Alde, Joseph Bitangcol, Alwyn Uytingco, and Valeen Montenegro.
Rainier Castillo started show business in 2003 and is still presently active. Among the television shows that he took part in are TV5’s Ang Utol kong Hoodlum, Midnight DJ, P.O.5, and LokoMoKo U. Also various shows of GMA Network like Full House, SRO Cinemaserye presents Reunion, Bubble Gang, Dear Friend: Bakasyonistas, Sine Novela: Paano Ba Ang Mangarap, La Lola, Codename: Asero, Tasya Fantasya, E.S.P.: When the Phone Rings, Kamandag, Bleach, Mga Kuwento ni Lola Basyang: Panadkyotyong, Bakekang, Majika, Hokus Pokus, Etheria, Now & Forever: Ganti, Love to Love (Season 6): Wish Upon A Jar, Mulawin, SOP Gigsters, SOP (Sobrang Okey Pare), Joyride, Click Barkada Hunt, Click (Philippine TV Series), Stage 1: The Starstruck Playhouse, Stage 1: Live!, and Starstruck.
He also made some films like Hellphone, Pangarap kong Jackpot: Bahay ni Lolo Hugo, OMG (Oh, My Girl!) which stars Judy Ann Santos, Ogie Alcasid, and Roderick Paulate, Ded na si Lolo, Rock & Roll, Shake, Rattle and Roll 2K5, Lovestruck, Happily Ever After, and So Happy Together which stars Kris Aquino, Eric Quizon, JR, Nova Villa, Gloria Diaz, Tonton Gutierrez, and his fellow Starstruck survivors, Jennylyn Mercado and Yasmien Kurdi. Of course, Rainier played the role of Yasmien Kurdi’s boyfriend in the said film. Rainier was also awarded as “Best Male New TV Personality” for his show, Click last 2004 PMPC Star Awards for TV.