Walgreens (Castro 24hr)

24-hour gym inside the Marriott Marquis, open to the public. Clean, modern, with showers and a steam room.

Well-stocked neighborhood 24hr convenience store. Grocery, frozen food, pet food, ice cream.

SF's most famous 24hr donut shop. Home of the giant donut challenge. Open since the 1960s.

24-hour hospital and ER. Listed for completeness as a late-night critical resource.