Soho Square is a garden square in Soho, London, hosting since 1954 a de facto public park let by the Soho Square Garden Committee to Westminster City Council. It was originally called King Square after Charles II, and a much weathered statue of the monarch has stood in the square, with an extended interruption, since 1661, one year after the restoration of the monarchy.

Of the square's 30 buildings (including mergers), 16 are listed (have statutory recognition and protection). During the summer, Soho Square hosts open-air free concerts.

By the time of the drawing of a keynote map of London in 1746 the newer name for the square had gained sway. The central garden and some buildings were owned by the Howard de Walden Estate, main heir to the Dukedom of Portland's great London estates.

At its centre is a listed mock "market cross" building, completed in 1926 to hide the above-ground features of a contemporary electricity substation; small, octagonal, with Tudorbethan timber framing. During the king's statue's absence through intercession of resident business Crosse & Blackwell it was a private garden feature at Grim's Dyke, a country house where it was kept by painter Frederick Goodall then by dramatist, librettist, poet and illustrator W. S. Gilbert of Gilbert and Sullivan fame.

Initial residents were relatively significant landowners and merchants. Some of the square remains residential. From the 1820s to the 1860s, at least eleven artists recently qualified for major exhibitions were resident aside from permanent residents, some of whom were more accomplished artists, as comprised in the local rate books; by the end of that century charities, music, art and other creative design businesses had taken several premises along the square. A legacy of creative design and philanthropic occupants lingers including the British Board of Film Classification, 20th Century Studios UK, Dolby Europe Ltd, Tiger Aspect Productions, Saint Patrick's Catholic Church which provides many social outreach projects to local homeless and addicts, the French Protestant Church of London (by architect Aston Webb) and the House of St Barnabas, a members' club since 2013, which fundraises and hosts events and exhibitions for homelessness-linked good causes.

Built in the late 1670s, Soho Square was in its early years one of the most fashionable places to live in London. It was originally called King's Square, for King Charles II. The statue of Charles II was carved by Danish sculptor Caius Gabriel Cibber during the King's reign in 1681 and made the centrepiece of the square; since it has returned it has not been in the centre. The development lease to convert the immediately surrounding fields, for 53+1⁄4 years, was granted in 1677 to Richard Frith, citizen (elector of the Corporation of London) and bricklayer. Ratebooks (of the vestry) continued to call the square King Square until the first decade of the 19th century; however, John Rocque's Map of London, 1746 and Richard Horwood's in 1792–99 mark it as Soho Square.

By the early 19th century, the statue, fountain and attendant figures was described as "in a most wretched mutilated state; and the inscriptions on the base of the pedestal quite illegible". In 1875, it was removed during alterations in the square by Thomas Blackwell, of Crosse & Blackwell, the condiment firm (which had premises at No. 20-21 Soho Square from the late 1830s until the early 1920s), who gave it for safekeeping to his friend, artist Frederick Goodall, with the intention that it might be restored. Goodall placed the statue on an island in his lake at Grim's Dyke, where it remained when dramatist W. S. Gilbert purchased the property in 1890, and there it stayed after Gilbert's death in 1911. In her will, Lady Gilbert directed that the statue be returned, and it was restored to Soho Square in 1938.

The politician William Beckford lived at No. 22 from 1751, and his son William Thomas Beckford, author of the Gothic novel Vathek, may have been born there.