The Scotland fly-half was forced off with a suspected groin problem in Bath's 21-15 European Champions Cup defeat by rivals Exeter on April 6.
Bath said the injury was "significant", raising fears the 31-year-old playmaker could miss the rest of the season.
But he has now been restored to the starting line-up for the club's match at Newcastle on Friday, where Russell will partner England's Ben Spencer at half-back.
Russell's return is timely for Bath as one of the most competitive seasons in Premiership history comes to a climax.
Bath are currently third in the table but sit just one point clear of fifth-placed Harlequins with two rounds of the regular season remaining.
The top four clubs at the end of the campaign will contest the title-deciding play-offs.
Russell's creative talents have been key to a revival in the fortunes of Bath, one of English rugby union's leading clubs of the 1980s and 1990s.
And his return to fitness will also be welcomed by Scotland ahead of their post-season tour of North and South America.
