Online Group Theory Seminars (organized by Chris Natoli)
Google calendar for online math seminars (organized by Ao Sun, Mingchen Xia)
Facebook online math seminars page
Online math seminars in your local time! (organized by Jaume de Dios)
Western hemisphere virtual symplectic seminar [Join]
Geneva Groups and Geometry Seminar Tu 16:30 Geneva
Geometry and Topology Online (Warwick)
Geometric Group Theory in East Asia (GGTEA) (Fridays 11 am, Korean time) http://ggtea.cayley.kr