The Algerian Football Federation said that Leekens, 67, had been chosen to replace Serbian Milovan Rajevac, who was sacked following Algeria’s home draw with Cameroon in the opening round of African World Cup group qualifiers earlier this month.
Leekens, who twice coached Belgium and was in charge of Tunisia at the 2015 African Nations Cup finals, returns to the post he held for six months in 2003 before quitting for "family reasons".
His first assignment with Algeria will be a World Cup qualifier away to Nigeria in Uyo on Nov. 12.
Algeria will then take part in the 2017 African Nations Cup finals in Gabon in January, where they have been drawn in Group B with Zimbabwe, Tunisia and Senegal.
Leekens left Lokeren after they lost 2-1 to Oostende in the Belgian league on Tuesday, which left them struggling near the foot of the table, having lost eight of their opening 12 games of the season.
The much-travelled coach had been at Lokeren for a year.
(Reporting by Mark Gleeson in Johannesburg; Editing by Toby Davis)
