The UEFA Pro Licence coach will be assisted by Marcall Trulls at the red and golds, the club said in a statement.
"Quess East Bengal FC (QEBFC) is pleased to announce the appointment of Mario Rivera Campesino as the Head Coach of the Senior Team till 31st May, 2020. Mario worked as an assistant coach with QEBFC last season under Alejandro. He is an UEFA Pro License coach and most of his coaching stints were in Spain," the club said in a statement.
The 42-year-old had assisted compatriot Alejandro Menendez at the club last season.
Two days ago, Menendez stepped down from his post after a spate of poor results saw the club languish at seventh place in the I-League table.
Rivera was earlier replaced by Josep Ferre as the assistant coach during the 2019/20 season after the 3-1 defeat against Gokulam Kerala on January 15.
Rivera is expected to take over the reins by the first week of February with fellow assistant Bastab Roy overseeing matters till then as they take on defending champions Chennai City FC on January 25 and Indian Arrows on February 1.
"Mario will arrive as soon as his visa formalities are completed," the club's release added.
East Bengal have lost three games in a row including their last fixture against arch-rivals Mohun Bagan in the Kolkata Derby to further dent their chances of winning the I-League after finishing second last season.
( With inputs from IANS )