Here is a list maintained by Fairfax County Recreation: https://www.fairfaxcounty.gov/neighborhood-community-services/athletics/sports-directory/youth-volleyball

I looked a while ago and the only thing I found was St James.

ST James always has leagues.

I believe NVVA also has leagues year round.

Virginia Elite has winter/spring “academies”- several sessions. Not sure if those are just a set of progressive clinics or if game play is included.

Are there any leagues or clinics in Northern VA?