Lagarde got the green light after MEPs voted 394 in favour of her presidency, with 206 against and 49 abstentions).
A formal appointment is expected in October, and she is set to replace Mario Draghi on 1 November.
Also on Tuesday: Yves Mersch was approved for the appointment of vice-chair of the ECB supervisory board, with 379 in favour. There were 230 votes against him, with 69 abstentions.