The trio will play a handful of shows in Spain, France and Italy in late June.
The jaunt will begin on June 22, with two shows at Barcelona's Poble Espanyol, before moving onto Vienne, France to play at the Theatre Antique de Vienne on June 25.
The next day they will perform at Verona's Castello Scaligero, before concluding at Rome's Ippodromo delle Capannelle on June 27.
Geoff Barrow recently stated that Portishead will work on a follow-up to 2008's Third in the near future.
The musician is also currently working on a Judge Dredd-inspired album.
The tour dates are as follows:
Poble Espanyol, Barcelona, Spain (June 22 and 23)
Theatre Antique de Vienne, Vienne, France (25)
Castello Scaligero, Verona, Italy (26)
Ippodromo delle Capannelle, Rome, Italy (27)
Watch Portishead perform 'Seven Months' in 1997 below: