"With his life and the example of aspiration for a better world, Belyatsky embodies the ideals of solidarity and working for others," Donskis said in a statement.
"I do believe the nomination of a person whose long-life activities in the field of human rights are based on good will and peaceful resistance for this prize will strengthen the prospects of international agreement and peaceful global development," he said.
Belyatsky established human rights center Vesna in 1996. The center has helped thousands of repression victims of "the last European dictatorship" in Belarus, Donskis said.
Belyatsky was jailed for four and a half years for tax evasion last November. The court also ordered seizure of all his assets. The case was based on bank data provided by Lithuania and Poland.
The West slammed the sentence, denouncing it as politically motivated. Lithuania apologized to Belyatsky's family and accused Minsk of abusing the international treaty for unlawful purposes.
EP political groups or MEPs have nominated five people for the Sakharov Prize this year.
