What episode of one piece does Nico Robin join the crew?

The Seventh One is Nico Robin!” is the 130th episode of the One Piece anime.

Does Robin join Luffy’s crew?

Nami’s official recruitment was when Luffy, Zoro, Usopp and Sanji defeated Arlong and his pirates. Robin was the first to initially willingly join, and then officially joined after Luffy’s crew came to her rescue from CP9.