Cher's rejection follows Russian president Vladimir Putin's decision to pass a law prohibiting adoption of Russian-born children to national and international same-sex couples.
The Grammy and Oscar winner explained that she has many friends who reside in Russia that "don't agree with what's going on with the government," and the fact that she has a transgendered child, Chaz Bono, had nothing to do with her decision.
"Chaz never even occurred to me," said Cher. "I have gay fans that have kept me working and given me a livelihood when nobody else was thinking I was that hot. In my low points they have never left."
In similar fashion, former Prison Break star Wentworth Miller turned down an invitation to attend the St. Petersburg International Film Festival last month.
"I cannot in good conscience participate in a celebratory occasion hosted by a country where people like myself are being systematically denied their basic right to live and love openly," Miller wrote in a letter to festival director Maria Averbakh.
Tune in to ET Tuesday night for more of Rob's interview with Cher. Fans can pick up her first album in 12 years, Closer to the Truth, when it drops September 24.