Embarcadero Plaza, previously known as Justin Herman Plaza from its opening in 1972 until 2017, is a 3.6-acre (1.5 ha) plaza near the intersection of Market Street and The Embarcadero in San Francisco's Financial District, in the U.S. state of California. It was completed in 1972 and is owned and operated by the San Francisco Recreation & Parks Department. The plaza is composed of two halves: Embarcadero Plaza North and Embarcadero Plaza South.

Embarcadero Plaza is bordered by Sue Bierman Park on the north, The Embarcadero on the northeast, Don Chee Way busway on the southeast, a combination of Steuart Street, Market Street, and Embarcadero Center on the southwest, and a combination of Embarcadero Center and Clay Street on the west.

Embarcadero Plaza North contains the Abraham Lincoln Brigade Monument, the Vaillancourt Fountain, a sunken brick hardscape, and temporary padel courts. Embarcadero Plaza South contains R-Evolution (Cochrane), bocce courts, the Don Chee Way hardscape, and a crosswalk.

The Ferry Building Park could be a great open space with canals, lagoons, and fountains that would revive the marine flavor by actually bringing the Bay back into the area. The atmosphere of European ports could be injected with handsome paving, sidewalk cafes, and fine restaurants. The freeway should be painted dark, and large trees should be planted to suppress its sight and its sounds. Difficult as all this may be, establish the Ferry Building Park area as a vibrant, alive, colorful place, used by day and at night, and it will send a tingle up the spine of Market Street.

The design of Embarcadero Plaza is credited to Don Carter (principal-in-charge) with help from Mario J. Ciampi and John Bolles. The original concept was devised by Lawrence Halprin, who described five distinct districts of Market Street in the 1962 report What to do About Market Street starting at the Embarcadero and ending at Van Ness. In retrospect, Halprin's vision for Market was described as a "pedestrian-oriented series of linked civic spaces" which were later realized as the open spaces running from Embarcadero Plaza (in the northeast) to UN Plaza in the southwest. Halprin described an early concept for what he called Ferry Building Park in the 1962 What to do About Market Street report, proposing to bring San Francisco Bay and the original harbor closer to Market, as "the [Embarcadero] Freeway and the Ferry building have created an impenetrable barrier, at street level, to one of San Francisco's most priceless assets – its marine setting" and offering ways to minimize the visual and aural impact of the double-decked freeway.

The controversial Vaillancourt Fountain dominates the northeast end of the plaza. The large plaza could accommodate large crowds, and the roaring fountain was designed to drown out noise from the Embarcadero Freeway, which was completed in 1959 and ran along the east side of the plaza from its opening in 1972 until the freeway was torn down in 1991.

The space occupied by Embarcadero Plaza was acquired in the 1950s and 1960s by the San Francisco Redevelopment Agency (SFRA). The space had been previously used for private buildings and parking before acquisition. The plaza was part of the Golden Gateway Redevelopment Project run by SFRA.

The designers of the plaza include Lawrence Halprin & Associates in conjunction with Mario Ciampi & Associates and John Bolles & Associates. The SFRA began construction of the plaza in the late 1960s, with construction finishing in 1972. The Vaillancourt Fountain, located on the Northern end of the plaza, was finished in 1971.