Celis, 19, made his way up the karting ladder in his homeland before moving to Europe to race in single-seaters. He has spent the 2015 season competing in Formula Renault 3.5 and in GP3, in which he scored his first podium at Spa-Francorchamps in August. He will get his first taste of F1 machinery in the end-of-season Pirelli test in Abu Dhabi on December 1.
"I would like to welcome Alfonso to the team and wish him well ahead of his debut with us in Abu Dhabi," said Force India team principal and managing director Vijay Mallya.
"As our development driver we will work hard to prepare him for the demands of driving in Formula One and provide a good grounding in all aspects of the job. It's a fantastic opportunity for Alfonso to learn from Sergio [Perez] and Nico [Hulkenberg], and to get valuable mileage in the car."
Celis, who will also spend time in the team's simulator as part of his new duties, added: "Ever since I started racing I've been dreaming of Formula One, so it's a huge honour to begin working with Sahara Force India.
"It's an amazing opportunity for me to learn about Formula One and to work closely with the engineers and race drivers. Being on the track in Abu Dhabi will be an incredible feeling. It's going to be the biggest moment in my career and I am fully focussed on doing a good job for the team."