The chapel was designed by
James Gibbs in 1722. It was originally intended as a
Chapel of Ease to supplement
the parish church for the growing parish of
Marylebone. The building was acquired by the Crown from the Portland Estate in 1817 and was dedicated to St Peter in 1832. In 1830, Parliament had passed an "Act for endowing the Parish Church of Newborough in the County of Northampton, and Three Chapels, called Portland Chapel, Oxford Chapel, and Welbeck Chapel, situate in the Parish of Saint Mary-le-bone, in the County of Middlesex, and also a Chapel erected on Sunk Island in the River Humber". It was licensed for marriages from 1722 to 1754 and between 1930 and its deconsecration:
Margaret Bentinck (daughter of the 2nd Earl, and Duchess of Portland) married here. Incumbents included the theologian
F. D. Maurice (1860–69), and
William Boyce was the chapel's organist from 1734 to 1736. Its interior appears in plate 2 of Hogarth's print series
Industry and Idleness. It was also here that the French chef Jassintour Rozea married his French wife Mary Magdalen Bernard in April 1744. They lived on Duke Street close to Grosvenor Square. He became Master Chef to the Duke of Somerset, Charles Seymour, presenting sumptuous banquets for his guests. He wrote several cookery books on gourmet French cooking in the 1750s. 's
Industry and Idleness, showing the interior of the chapel St Peter's served the congregation of
All Souls Church, Langham Place, from 1940 to 1951 whilst the latter was having war damage repaired, and then became a chapel of ease to it. ==Architecture==