Indy Lights champion replaces Hawksworth at former Indy 500-winning team.
Reigning Indy Lights champion Gabby Chaves will step up to the IndyCar series next year after securing a deal with the Bryan Herta Autosport team.
The 21-year-old Colombian beat Briton Jack Harvey to the Lights title last year, earning a scholarship towards an IndyCar drive for 2015.
"I'm so excited and honored to be the latest Colombian driver in IndyCar," said Chaves.
"It's been an incredible journey and to finally become an IndyCar driver is an awesome feeling and the start of a great future."
Chaves had tested for the team at the end of last year before securing the race drive.
"We're excited to have Gabby join the team this year," said Bryan Herta. "In December we had the opportunity to test him at Sebring and his speed and feedback were very impressive.
"Gabby has the skills and mindset to make a real impact in IndyCar, I see no reason why Gabby should not be a top contender for Rookie of the Year honors."
Chaves will replace Jack Hawksworth at the team, the Briton moving to AJ Foyt Racing for the upcoming season.