The US basketball star was sentenced to nine years in jail on Thursday.
The pop megastar took to social media to offer his help in getting the athlete home after she received a sentence of nine years in prison for bringing cannabis oil into Russia.
Writing on his Instagram story, the 28-year-old singer said: “this hurts.
“If anyone knows any way I can help please let me know.”
31-year-old Griner, a two-time US Olympic champion who plays for the WNBA’s Phoenix Mercury, was handed the sentence by Judge Anna Sotnikova on Thursday.
Other celebrities reacting to the news included Jada Pinkett Smith, Mia Farrow and rapper 50 Cent.
Pinkett Smith wrote: “On the same day we got justice for Breonna (Taylor)… I find out that Brittney Griner just got nine years in Russia #FreeBrittney.”
Actress Farrow said the news was “heartbreaking”.
“The Russian judge ignored everything Britney Griner had stated,” she tweeted.
He sentenced her to nine years in a ‘penal colony’ for carrying two vaping cartridges, which were medically prescribed.
50 Cent, real name Curtis Jackson, said: “This is wild, smh (shaking my head).”
“You don’t ever want to get caught up in the politics, They are gonna tell her like 10 years for a vape pen, watch.”