Gutierrez has long been touted as a possible Sauber recruit due to his role as the team's test driver, and fellow Mexican Sergio Perez - who is on his way to McLaren from the Swiss outfit - revealed yesterday that the 21-year-old had got the nod.
Gutierrez replaces Kamui Kobayashi and from next season will partner Nico Hulkenberg, who is leaving Force India.
Gutierrez, who steps up to F1 after two seasons in GP2, said: "After three years working with Sauber I feel very grateful for all the attention I have received from everyone in the team and for all their input, which has allowed me to develop into a Formula One driver in a very progressive way.
"Now, after experiencing other categories of racing as an introduction to Formula One, this is the start of the real challenge to succeed at the pinnacle of motor sport.
"It will be a great pleasure to be racing in the same team as an experienced driver like Nico Hulkenberg. He will be a good reference point for me and will push me to adapt quickly to F1 competition so we can develop the car together with the team in the best way."
Sauber team principal Monisha Kaltenborn added: "Esteban has already been part of the team for a long time and we have followed his career very closely.
"In 2010 we signed him up as an affiliated driver, and in 2011 and 2012 he was our test and reserve driver.
"We mapped out his path to Formula One step by step. Esteban has great talent and now he's ready to take the leap.
"We are in no doubt we have a strong driver pairing in place for the 2013 season with Nico and Esteban."
Sauber have also confirmed 21-year-old Dutchman Robin Frijns as their new test and reserve driver.