Come de Cherisey, who heads the prestigious gastronomic guides - second only to the Michelin - said the Russian investors have promised to pump several million euros into the company.
"I helped internationalise and digitise the guides over the past seven years, now we need the means" to follow through on that, Cherisey added.
The new owners are linked to the state-owned VTB, one of Russia's top banks, which has been hit by both EU and US sanctions since Moscow annexed Crimea from Ukraine in 2014.
Cherisey refused to say how much he sold the 100 percent stake in Gault & Millau for, but said the new Russian owners would be investing "several million euros in the short term".
They are represented by Moscow lawyer Vladislav Skvortsov. The guide's new chairman Jacques Bally said they had big plans to "develop in France and abroad while remaining true to Gault & Millau's historic values."
The first Gault & Millau guide was published in 1969 and helped whet the world's appetite for nouvelle cuisine.