Grabeel was born in Springfield, Missouri on November 23, 1984, the son of Jean (née Harman) and Stephen Grabeel. Before transferring to and graduating from Kickapoo High School in Springfield in 2003, he attended Logan-Rogersville Elementary, Middle and High School. He also played drums for a local church and initiated a men's a cappella singing group at a high school. At school, he found passions in the guitar and the accordion while also enjoying dance. He can dance in the styles of jazz, ballet, hip-hop and tap. While in Rogersville, Missouri, he regularly attended Harmony Baptist Church, where he was a part of the children's and youth groups. During the summer of 2002, He attended the Missouri Fine Arts Academy (MFAA) at Missouri State University. In a letter written to protest eliminating MFAA, Grabeel stated, "I wouldn't be where I am at if it weren't for my time at MFAA." His time there, as he refers to it, is what led him to move to LA and pursue an acting career.
Following his graduation, Grabeel moved to Los Angeles to become an actor. After two months living there, Grabeel landed his first television role in a commercial for toothpaste and then eventually went to star in other commercials for Lego and Hot Wheels. Soon after, he starred in his first film role as Ethan Dolloway in the third installment of the Halloweentown seriesHalloweentown High. He subsequently reprised this role in the series' fourth installment Return to Halloweentown.
Since the summer of 2011, Grabeel has been starring in the ABC Family drama Switched at Birth, in which he plays the brother of one of the two girls that were mistakenly switched at birth in the hospital.
Aside his involvement in the High School Musical soundtracks, Grabeel has recorded a song called "You Know I Will" for the soundtrack of The Fox and the Hound 2 and also recorded his own version of the Michael Bolton track "Go the Distance", from Disney's Hercules, for DisneyMania 5. In 2007, Grabeel co-wrote and recorded a song called "You Got It" which was released on iTunes on August 19, 2007 while its accompanying music video was released on his official website. Grabeel also recorded another original song called "Trash Talkin'" which was released November 15, 2008 on YouTube. Grabeel also sings in the iTunes show I Kissed a Vampire, in which, he stars. In early 2009, he appeared at the Southland Theatre Artists Goodwill Event (S.T.A.G.E.), an AIDS charity event, in Beverly Hills performing George and Ira Gershwin's "I Can't Be Bothered Now". He also recorded and released a new track titled '135n8' in early 2014 with the music video being uploaded to his YouTube account.
In 2007, Grabeel founded a production company called 14341 Productions. His role within involves overseeing many projects from writing, directing and executive producing. The company have produced projects such as the short filmsThe Real Son, Smoke Break; the music videos for "Get Your Ass On" and "You Got It". They also produced a TV pilot called Regarding Beauregard which was Grabeel's directorial debut. They are currently working on a short film, The Adventures of Chuckle Boy, and have just released a short film The Dragon. They debuted their work at the 2009 Sundance Film Festival.