Park Tower at Transbay, Office skyscraper in South of Market, San Francisco, United States.

Park Tower at Transbay is a 43-story, 605-foot (184 m) office skyscraper at Beale and Howard Streets, clad in reflective blue glass panels arranged in a grid. Near the top, three stacked, open-air cantilevered sections project from one side. The tower contains 743,000 square feet (69,000 m2) of office space, all leased by Facebook.

The site was formerly occupied by the old Transbay Terminal's state-owned ramps before the land was redeveloped for this office tower. The construction project emerged in the 2010s as part of a broader urban renewal effort in the South of Market neighborhood.

The tower's office space is entirely leased by Facebook, which signed on before the building opened. Its lobby was designed by the firm Interior Architects. The site sits on Block 5, a parcel bounded by Howard, Main, Beale and Natoma Streets, split by a driveway serving the neighbouring Providian Financial Building.

The tower connects directly to a major transit center, making it easily accessible by public transportation from across the city. Visitors should know that this is a private office building with limited public access to its interior spaces.

The winning proposal came from Golub Real Estate and The John Buck Company, working with Goettsch Partners and Solomon Cordwell Buenz. Their design was chosen over entries from Boston Properties with Kohn Pedersen Fox, Jay Paul Company with Skidmore, Owings & Merrill, and Kilroy Realty with Pelli Clarke Pelli.