Villas-Boas, who began his coaching career at Porto as an assistant to Jose Mourinho, guided them to a treble in 2011 which included the Europa League crown.
He earned 21,489 votes in Saturday's election and won by an 80.3% majority.
"Winning, winning titles and sustaining our club for the future is what I want," Villas-Boas said in a statement.
"It's a victory for Porto's members. Because of the responsibility they give me, I promise to give my life for Porto...
"Our club is alive and today it showed its strength. I launched this candidacy for the club and its members. I received the strength, energy and confidence that has brought us this far."
Villas-Boas hailed the influence of Pinto da Costa, who took charge of Porto in 1982 and led them to 27 league titles and two Champions League trophies.
"I would like to thank him for everything he has given to Porto, for the life he has given to Porto, and I would like to assure him that this is and always will be his home," Villas-Boas said.
Porto have had a disappointing season and sit third in the Portuguese top flight. They lost to Arsenal in the Champions League's last 16 and have been eliminated from Portugal's cup competition.