The former Athletic Bilbao coach had long since been linked with the role at Stade Velodrome and the Ligue 1 club have now revealed that he is set to sign a two-year deal in the coming weeks.
Jose Anigo has been in temporary charge of Marseille since Elie Baup was sacked in December, but will step aside at the end of the campaign as 58-year-old Bielsa prepares to take charge.
A statement released by the club on Friday read: "A contractual agreement on the commitment of Mr Marcelo Bielsa to the post of coach of Olympique de Marseille for the next two football seasons has been found.
"It was agreed between the parties that the formalisation of commitment will materialise in a formal signing of his contract when he next comes to Marseille at the end of the season."
Bielsa is vastly experienced not only at club level, but having taken charge of his native Argentina as well as South American rivals Chile.
During his time at Bilbao, he led the club the final of the Copa del Rey and the UEFA Europa League and experienced success in previous stints at Newell's Old Boys and Velez Sarsfield in his homeland.
Marseille sit sixth in Ligue 1 with three games remaining.
