- Sports Wellness And RecreationSilicon Valley Rugby Football ClubSouth Bay rugby football club with adult rugby teams and community participation.
- Sports Wellness And RecreationSilicon Valley Triathlon ClubSouth Bay triathlon community for swimming, cycling, running, racing, and social connection.
- Arts And CraftsSilicon Valley WoodturnersSouth Bay/Silicon Valley woodturning club for turners, demos, and learning.
- Business And CareerSilicon Valley Young Professionals (SVYP)SVYP is a council within the SV Chamber focused on young professionals, with bi-monthly meet-ups that often take the form of happy hour mixers; informally under-40 ('we do not card at the door').
- Social And MeetupsSIR Branch 161 (Sons In Retirement)A branch of Sons In Retirement, a nonprofit public benefit organization for men, with members from Discovery Bay, Brentwood and surrounding communities; activities include bowling, golf, pickleball, tennis, RVing, cycling and wine tasting.
- Books And WritingSisters in Crime Northern CaliforniaRegional chapter/community for mystery, crime, and thriller writers and readers.
- Sports Wellness And RecreationSnowchasers Ski & Snowboard ClubConcord-based ski and snowboard club formed in 1983; a year-round activities and social club for families, couples and singles in the East Bay, with a recreational race team and affiliation with Bay Area Snow Sports Council and Far West Ski Association.
- Social And MeetupsSocial San Francisco: Events for IntrovertsA group for introverts in San Francisco to socialize and make friendships in relaxed environments.
- Business And CareerSociety of Women Engineers - Bay Area SectionsUmbrella-style row for Bay Area SWE sections supporting women engineers through events, networking, outreach, and leadership.
- Sports Wellness And RecreationSolano Community Tennis Association (SCTA)A 501(c)(3) community tennis association founded in 2021 to promote and develop the growth of tennis in northern Solano County (dba Northern Solano County Racquet Association); supports USTA adult league play at Centennial Park, a Pickleball Division (dba Vacaville Pickleball), and GO Solano youth programs.
- Arts And CraftsSOMArts Cultural CenterSOMArts leverages the power of art as a tool for social change through multi-disciplinary events and exhibitions. Equipping artists with the space, mentorship and support they need to shift perspectives and innovate solutions to today’s pressing challenges, SOMArts fosters access to arts and culture for collective liberation and self-determination.
- Sports Wellness And RecreationSonoma County Adult Coed Soccer LeagueRecreational outdoor coed soccer league for adults in Sonoma County (men over 30, women over 18); season runs March through end of June with Saturday games at Galvin and Trione parks and Santa Rosa/Piner high schools.
- Nature Gardens And FarmsSonoma County Beekeepers AssociationSCBA supports Sonoma County residents interested in honey bees, beekeeping, pollinator habitat, and community, with educational activities, a swarm-rescue program, and a newsletter.
- Books And WritingSonoma County Genealogical SocietyThe purpose of this Society is to educate the general public and members in genealogical research, and to preserve, collect, compile, publish and disseminate genealogical data and family history. Publishes the Sonoma Searcher.
- Nature Gardens And FarmsSonoma County Mycological Association (SOMA)The Sonoma County Mycological Association (SOMA) is a non-profit group dedicated to learning about local mushrooms and fungi, supporting mycological research through scholarships and educating the public. Hosts forays, SOMA Camp, and a Mushroom Art Fair.
- Sports Wellness And RecreationSonoma County Pickleball ClubOrganizes drop-in pickleball play at public courts throughout Sonoma County, including daily 9am drop-in at Finley Park and afternoon play at Howarth Park in Santa Rosa, plus locations in Petaluma, Windsor, Rohnert Park, Healdsburg, Sebastopol and more.
- Science Tech And CodingSonoma County Radio AmateursSonoma County ham radio club holding monthly membership meetings with programs of interest to hams, VE license exam sessions, repeaters, and ARRL Field Day participation.
- Food And DrinkSonoma County Women's Wine Club (SCWWC)Group for women in Sonoma County who enjoy networking, socializing, and drinking wine, meeting monthly at local wineries, small businesses, and restaurants. Must be 21+ to join.
- Books And WritingSonoma Reads! Book ClubMeets the fourth Thursday of the month from 2-3 pm. Pick up a copy of each month's book at the Sonoma Valley Branch while supplies last. Then, please come and discuss it with us.
- Sports Wellness And RecreationSonoma Splash Masters SwimmingMasters swim team at Sonoma Splash's aquatic center welcoming brand new swimmers, returning swimmers, and regulars who want to work out with a group; coached by USMS-certified coaches; offers a 'Masters 101' intro class.
- Social And MeetupsSouthbay Cope-a-cabana singles and couples Social ClubSouth Bay club for singles and couples featuring weekly poker nights plus karaoke in 20+ languages, open mic, ping pong, backgammon, swimming pool and hot tub get-togethers.
- Games And TabletopSouth Bay Historical Railroad SocietyThe South Bay Historical Railroad Society (SBHRS) was incorporated in 1985 to preserve the local area railroad heritage while running a working museum at the historic Santa Clara Depot. Admission is free.
- Arts And CraftsSouth Bay WoodworkersWoodworking club/community with meetings, education, and skill sharing for woodworkers.
- Books And WritingSouth Bay Writers (California Writers Club)South Bay branch of the California Writers Club with monthly speaker meetings, open mic nights, contests, and a newsletter for writers.
- Sports Wellness And RecreationSouth End Rowing ClubThe South End Rowing Club, founded in 1873, is one of the oldest athletics clubs in the western United States. The club supports participation in rowing, swimming, handball, and running.