The 26-year-old is the first driver signed to one of the new F1 teams joining in 2010.
"It is a great pleasure to welcome Bruno Senna in the team," Campos chief executive Enrique Rodriguez de Castro said in a statement.
De Castro described Senna as "one of the most promising up-and-coming drivers of his generation."
"For Campos Meta 1 it is an extraordinary honor to be returning the name Senna to Formula One."
Senna was close to joining Brawn GP ahead of the 2009 season, but that seat was ultimately filled by Brazilian compatriot Rubens Barrichello.
"I'm absolutely delighted to fulfill a lifetime dream," Senna said. "After many weeks of hard work and negotiations, me and my management finally made it."
The deal brought the approval from F1 boss Bernie Ecclestone.
"It's good for everybody - good for Campos, good for him and good for the sport," Ecclestone said. "I hope the car is up to him, that's important."
Ecclestone also hinted at the Spain-based Campos signing Nelson Piquet Jr. to partner Senna next season, creating a union of two of the biggest family names in F1 history.
"It'd be good wouldn't it, another good name," Ecclestone said. "That's what's being talked about actually."
Ayrton Senna won the F1 title in 1988, 1990 and 1991 before being killed in an accident at the 1994 San Marino Grand Prix.
Brazil's Piquet, son of the former world champion of the same name, was fired by Renault this season and his subsequent revelations about deliberately crashing in the 2008 Singapore Grand Prix rocked the sport and led to long bans for key Renault staff.
Campos had been linked with McLaren test driver Pedro de la Rosa to add experience and also a Spanish presence for the team.
However Campos said its links with South America were also part of the team identity.
"The deal with Senna confirms and reinforces our prime objective of being not only the first Spanish Formula 1 team, but rather the first Iberian-American F1 team," Rodriguez de Castro said.
The Senna announcement answered the growing number of doubters questioning the ability of Campos and the other new 2010 teams - Manor, Lotus and USF1 - to make it to the grid next season.
"There is no reason to have any doubts," Ecclestone said. "They've entered and presumably they know what they are doing."
