Another accused, Akhmed Yevloyev, was given 10 years in jail.
The suicide terror attack in Domodedovo international airport left 37 people dead and over 170 injured in January 2011.
The four had assisted the suicide bomber, Magomed Yavloyev, a brother of one of the accused, to travel to Moscow from Ingush republic in the North Caucasus and made a bomb for him, the ruling said.
Several other men suspected of helping the bomber were killed by security forces during special operations earlier.
Doku Umarov, a Chechen warlord, had claimed responsibility for the attack later.
Also, the Russian criminal investigation organization, the Investigative Committee, Monday said the law enforcement agencies "continue to actively work" on detaining Umarov in connection with Domodedovo bombing and other terror attacks in Russia, including twin bombings in Moscow subway in 2010.
The ruling has not come in force yet as the defendants have 10 days to appeal.