The Dutchman steps up after several seasons racing in GP2.
"I know I am ready to take the step up to F1 and all the work I have done throughout my career, and particularly in the last year with this team, has brought me to my ultimate goal."
"Throughout 2012 I was able to fully integrate myself into the team, both through the FP1 sessions I ran at a number of tracks that were then new to me, and as reserve driver, fully embedded with the team throughout the season."
"Now I can continue to learn at the highest level of motorsport and show that I am ready for F1. I cannot wait to start work."
"Everyone in the team is delighted that we can finally confirm that Giedo will be racing for us in the 2013 FIA Formula One World Championship," added team principal Cyril Abiteboul. "He has been part of our family since early 2012 when he joined our GP2 team and was appointed as Reserve Driver for the F1 team. He acquitted himself extremely well in both his GP2 season and his six FP1 sessions, progressively improving his outright pace, technical feedback and his relationship with his engineers and mechanics, giving us the clear justification for promoting him to F1."
Caterham's announcement means that a Dutch driver will race in the sport for the first time since 2007.
Van der Garde will race alongside Charles Pic; the two were team-mates in GP2 in 2011.