The deal ensured the future of the league - a league which NBA commissioner David Stern had threatened with oblivion had it not reached a deal. Stern is already expecting to pump more than $12m into the struggling league in the coming year.
The four-year deal, with an option for a fifth, includes a tough salary cap and free agency - the first time such a condition has been incorporated into women's pro sports.
Said WNBA president Val Ackerman: "We are moving full force ahead.
"More than anything now that this process is over, we are very much looking forward to rolling up our sleeves and getting down to the business of building on the foundation that our players have established over the last six years."
Added Pam Wheeler, the union's director of operations: "In the area of free agency, not only is it a milestone in terms of women's sports, but the level of free agency we were able to achieve is unprecedented.
"In most other sports it takes years before a person can be a restricted or unrestricted free agent. We're proud of those landmarks."
