Hulk signed with the Chinese Super League outfit after passing a medical on Thursday.
The 29-year-old scored 74 goals in 148 appearances for Zenit following his arrival from Porto for €40m in 2012.
SIPG finished second in the league last season under the guidance of former England coach Sven-Goran Eriksson.
China has attracted a slew of big-name players in recent years, including Ramires, Alex Teixeira, Ezequiel Lavezzi, Jackson Martinez and Gervinho.