- Nature Gardens And FarmsNapa-Solano Audubon SocietyAudubon chapter for Napa and Solano counties offering birding field trips, weekly Saturday bird walks, a monthly speaker series, K-12 education programs, citizen science, and conservation advocacy.
- Games And TabletopNapa Valley Model Railroad Historical SocietyModel railroad historical society with a STEM education focus, participating in regional model railroad events.
- Arts And CraftsNapa Valley QuiltersQuilt guild that invites area residents and guests to join; meets monthly at the Napa Senior Citizens Center. Mailing address P.O. Box 405, Napa, CA 94559.
- Social And MeetupsNewcomers' Club of San Mateo CountyA 501(c)3 non-profit social group for all San Mateo County residents, founded by Ida Lindau in 1949 as the San Mateo Newcomer's Club and renamed in 1998.
- Social And MeetupsNiles Rotary Club of FremontA group of business and civic-minded individuals and leaders being the change we want to see in Fremont and the world.
- Sports Wellness And RecreationNob Hill Run Club3 mile runs, Saturdays in Marina Green, check out linktree for deets!!! all paces & beginner runners are welcome
- Sports Wellness And RecreationNon-Binary Run Club SFnon-binary run club is celebrating, uplifting, and providing a training community for trans and non-binary runners.
- Sports Wellness And RecreationNor Cal AquaticsA fun social masters swim group for all ages and abilities; some swimmers compete in pool and open water events; triathletes, beginners, and fitness swimmers welcome. Trains at Health Quest Fitness in Napa and Lake Berryessa.
- Sports Wellness And RecreationNorth Bay AquaticsOffering practice 7 days a week, NBA serves the North Bay for swimmers looking for coached practices while having a lot of fun, from beginning to highly competitive levels.
- Outdoors And AdventureNorth Bay Rowing ClubRowing club in Sonoma County offering junior crew (middle school learn-to-row and high school competitive teams), adult programs, and summer camps on the Petaluma River.
- Culture And LanguageNorwegian Club of San FranciscoPrivate nonprofit organization promoting fellowship among the Norwegian-American community in the San Francisco Bay Area.
- Social And MeetupsNovato Mothers ClubCreated in 1993 to provide mothers with a supportive nurturing environment, knowledge through shared experiences, friendship, and activities; members enjoy playgroups, family events, moms' nights out, and a quarterly newsletter.
- Outdoors And AdventureNo Worries Amigo Hiking ClubBay Area hiking club/community focused on organized hikes and social outdoor connection.
- Business And CareerNSBE San Francisco Bay Area ProfessionalsProfessional chapter for Black engineers and technologists with networking, programs, and community activities.
- Games And TabletopOakland Chess ClubThe Oakland Chess Club (OCC) is one of the premier chess organizations in the San Francisco Bay Area. OCC provides a friendly environment for players of all ages and skill levels to enjoy the game of chess.
- Social And MeetupsOffbeat San FranciscoOffbeat San Francisco is a Meetup group exploring unique, unusual, and offbeat attractions and events in the city.
- Nature Gardens And FarmsOhlone Audobon SocietyA chapter of the National Audubon Society. Our mission is to celebrate and protect birds and their habitats in Southern and Eastern Alameda County
- Science Tech And CodingOhlone Audubon SocietyA chapter of the National Audubon Society whose mission is to celebrate and protect birds and their habitats in Southern and Eastern Alameda County, with field trips, membership meetings, classes, and youth education.
- Sports Wellness And RecreationOlympic Club TennisTennis has a long history, but the birth of the game played today is thought to have taken place in England. Played on a rectangular court lined for singles and doubles, players wield stringed rackets and hit the ball over a regulation tennis net, which divides the court in two. A point is a single exchange in which opposing players win by hitting the ball within the lines but out of reach of their opponent, or if their opponent hits the ball outside the lines or into the net.
- Science Tech And CodingOpenTelemetry Meetup San FranciscoMonthly Bay Area meetup around OpenTelemetry and open-source observability for DevOps, SRE, and software teams.
- Science Tech And CodingOWASP Bay Area ChapterBay Area chapter of OWASP for application-security professionals, talks, and community events.
- Sports Wellness And RecreationOyster Bay Disc Golf ClubOyster Bay Disc Golf Club was incorporated as a non-profit public benefit corporation to support and maintain the Oyster Bay Disc Golf community
- Outdoors And AdventureOyster Point DragonsA 501(c)(3) all-volunteer dragon boat team founded in 2012 and based at Oyster Point Marina; mission is to promote dragon boating in a fun and safe environment while fostering team spirit and friendship; includes adult, middle school (Tiger Sharks) and high school teams.
- Games And TabletopPacific Mahjong LeagueCompetitive riichi mahjong league using modern Japanese riichi rules with a published rulebook, welcoming both seasoned competitive players and curious beginners.
- Sports Wellness And RecreationPacific Masters SwimmingRegional Masters swimming network for adult swimmers with clubs, workouts, meets, clinics, and social functions.