Late Nemtsov, a vocal Kremlin critic and deputy prime minister in the late 1990s to President Boris Yeltsin, was shot dead in February 2015 as he walked with his girlfriend in central Moscow.
Former Chechen soldier Zaur Dadaev, who investigators say acted as the gunman, was handed a 20-year sentence, while Four other men all of whom were convicted of being accomplices in the same court last month were handed terms ranging between 11 and 19 years.
All five will serve their time in a high-security penal colony.
Moscow's District Military Court also fined each man 100,000 rubles ($1,670). The trial of the five men began in October 2016, seven months after the suspects were arrested.