When did Russia join G7?

Following the collapse of the Soviet Union in 1991 and a subsequent thaw in relations between the East and West, Russia was also invited to join the group in 1998. Thereafter the group was named the G8 until 2014.

For more details on Group of Seven (G7) is available on the given link.

Further Readings-

1. List of Important Summits in 2021 
2. Group of Eight (G8)