noun, plural co·chair·men. one of two or more joint chairmen.

How do you write Co-Chairman?

Both are correct, it depends on what you want to say. Co-chairman is a person, Co-chairmen means more than one person.

Can you have a co-chairman?

The Board may appoint one or more of its members to be Chairman or Co-Chairmen of the Board. ... Such offices may include a Chairman or two or more Co-Chairmen of the Board of Directors, a President or two or more Co-Presidents, one or more Vice Presidents, a Secretary and a Treasurer.