The midfielder, who donned the armband in 2004 under Jose Mourinho’s leadership, is also skipper in Fabio Capello’s England squad. However, he was stripped of the national title for a year in 2010 due to allegations regarding his private life.
"John is the captain of this club and will continue to be, as long as he can perform to the utmost of his ability as he has in the last six years,” the manager said.
"He has been successful in his captaincy for most of the time. And he represents the successful history of this club in the last six or seven years.
"I know most of the players in the dressing room see John as a leader and a player who motivates them. So, if John is in the team, he will be the captain."
Villas-Boas said that there are many equally worthy players in his squad, but added that he expects them to set a good example off the pitch.
“If we find other leaders, more social role models, for sure they will have the captaincy as well,” he explained. "Like Lamps and Didier who have taken the captaincy in different games.
"Because in the end, it's not a question of saying John is the only leader. There are lots of leaders in the dressing room."
The 33-year-old yesterday unveiled former Blues player Roberto Di Matteo as his assistant manager.