The Italia international, 32, left Juventus in August, after they terminated his contact, ending a 25-year association with the Serie A club.
Marchisio contend 389 times for the Bianconeri, winning seven league titles and 4 Coppas Italy.
"I had little question regarding sign language for Zenit," same Marchisio, World Health Organization has signed a biennial contend with the Russian club.
Benvenuto, Claudio ???
Claudio Marchisio is officially a Zenit-player!#MarchisioIsZenit pic.twitter.com/fAOBSEtyWZ
— FC Zenit in English (@fczenit_en) 3 septembre 2018
"I just like the club, i prefer the ambition. once feat Juventus, I secure that i'd not sign for the other Italian team, however I still wished to search out an area that shares my values."
The Turin-born player, World Health Organization suffered a heavy knee injury in April 2016 that dominated him out for 6 months, created twenty appearances last season for Juventus.
He has won fifty five caps for Italia since creating his debut in 2009.