7 and 8 Balfour Place are a pair of Grade II listed houses in Balfour Place, Mayfair, London W1, on the corner with Mount Street. No 7 is also known as Balfour House.

7 and 8 Balfour Place were Grade II listed in 1984.^[1] They were built in 1892–1894 by Eustace Balfour and Hugh Thackeray Turner of Balfour and Turner, in a "Free Style with Flemish and early Renaissance details" , or in an Arts and Crafts style.^[1][2] The house's first owner was George Coventry, 9th Earl of Coventry.^[3] Balfour Place was originally known as Portugal Street (honouring the Portuguese wife of King Charles II), until the Grosvenor family renamed it after their chief surveyor.^[2]

In 1978, the heiress Christina Onassis, who owned a three-bedroom flat in nearby Reeves Mews, flew in to London for a one-day shopping tour, amid considerable press interest.^[2] She viewed the house, but was apparently put off by the de Grimston co-founders of The Process Church of The Final Judgment, living in the street, and the press calling their property "Satan's Cave".^[2]

In 1991, the house was converted into six flats.^[4]

In 2014, it was listed for sale at £45 million, with seven reception rooms, 19 bedrooms, six kitchens and 17 bathrooms".^[5][6]

In 2016, billionaire British banker Peter Cruddas and his wife Fiona paid £42 million in cash for the seven-storey mansion, formerly owned by the Iranian-born art dealer Nasser Khalili, who lived there for 22 years.^[4]