Couples come from all over the world to be married in San Francisco and of all the wonderful city-wide locations in which to exchange your vows, San Francisco City Hall, with all its splendor, is one of the most popular! I've personally officiated for couples who have travelled here from Australia, China, England, France and Ireland; and many Bay Area residents and vacationing couples from other parts of California and our nation.
As a result of its popularity, dropping in at the San Francisco County-Clerk's office without an appointment expecting to obtain your marriage license and to be married all in the same day is not only UNrealistic, it just simply won't happen for you. Because of demand, "The City" handles ALL marriage licensing affairs and ceremonies solely by appointment.
The best place to get all the details including licensing fees, etc. is from the San Francisco City/County Clerk's office themselves, click here to be directed to their site.