Carlos was born in Columbia, Missouri and raised in Weston, Florida. His father is of Spanish and Venezuelan descent, and his mother is of Dominican descent.He attended Sagemont Upper School where he was a cheerleader. Carlos attended the American Heritage School where he was in a production of Titanic. During his run in Titanic he fell in love with singing and dancing.
His first acting role was a guest star at age ten on ER, followed later that year by guest-starring roles on Judging Amy, Summerland, and Ned's Declassified School Survival Guide.Pena was studying musical theater at the Boston Conservatory when his manager urged him to audition for Big Time Rush. Although he was reluctant to do so, he submitted an audition tape and won the role almost 2 years later. Afterwards, he moved to Hollywood.In 2009, he formed the band Big Time Rush along with Kendall Schmidt, James Maslow, and Logan Henderson and star in the tv show of the same name.
On January 4, 2014, he married actress Alexa Vega, and they combined their last names to PenaVega. On June 16, 2016, the couple announced via Instagram that they were expecting their first child. Their son, Ocean King PenaVega was born on December 7, 2016