Foundry Square is a complex of four architecturally-linked, 10-story mid-rise buildings located at Howard and First Streets near the Salesforce Transit Center in the South of Market neighborhood of San Francisco, California.

The four structures combined provide a total interior area of 1,200,000 square feet (110,000 m2).

Current tenants include the law firm of Orrick, Herrington & Sutcliffe, STUDIOS Architecture, the headquarters of Slack, and the NASDAQ Entrepreneurial Center.

In April 2012, Tishman Speyer acquired the entitlements to the final building, Foundry Square III (505 Howard Street), from Wilson Meany Sullivan, and broke ground later that year.

The project earned SWA Group the ASLA Northern California Chapter Merit Award in 2006.