St Mary le Strand is a Church of England church at the eastern end of the Strand in the City of Westminster, London. It lies within the Deanery of Westminster (St Margaret) in the Diocese of London. The church stands on what was until 2021 a traffic island to the north of Somerset House, King's College London's Strand campus, and south of Bush House (the former headquarters of the BBC World Service which became part of King's College London). The foundation was part of an extensive new church building effort in the early 1700s (Queen Anne Churches). It is the official church of the Women's Royal Naval Service, and has a book of remembrance for members who have died in service. It is known as one of the two 'Island Churches', the other being St Clement Danes.

The church is the second to have been called St Mary le Strand, the first having been situated a short distance to the south. It was mentioned in a judgment of 1222, when it was called the Church of the Innocents, or St Mary and the Innocents. It was pulled down in 1549 by Edward Seymour, 1st Duke of Somerset, to make way for Somerset House. The parishioners were promised a new church, which was never built, forcing them to move to the nearby church of St Clement Danes and afterwards to the Savoy Chapel. The site occupied by the modern church was formerly occupied by a great maypole, which had been the scene of May Day festivities in the 16th and 17th century and was severely decayed by the early 18th century.

The new St Mary le Strand was the first of the twelve new churches built in London under the Commission for Building Fifty New Churches, at a cost of some £16,000. Construction began in February 1714 under the architect James Gibbs, being his first major project following his return from Italy. The steeple was completed in September 1717, and the church was consecrated for use on 1 January 1724, by Edmund Gibson, Bishop of London, when John Heylyn became first rector of the rebuilt church. Bonnie Prince Charlie is said to have renounced his Roman Catholic faith in the church to become an Anglican during a secret visit to London in 1750. John Dickens and Elizabeth Barrow, the parents of Charles Dickens, were married here in 1809.

It was restored in 1871 by Robert Jewell Withers, who removed the box pews and had them re-formed into the elegant benches with scrolling sides that one sees in the church today. The tiled floor in the nave and chancel are also his doing.^{[citation needed]}

The Church Times said

RE-OPENING OF THE CHURCH OF ST MARY-LE-STRAND —This church, which has been closed for several months, undergoing extensive alterations and thorough restoration, was re-opened for Divine service on Sunday morning. The whole of the unsightly and inconvenient pews have been removed, and replaced by free and open seats. The chancel has been greatly improved, and the whole of the church has been re-decorated with exceeding taste. In fact, the renovated ceilings of the nave and chancel, together with the tastefully coloured walls of this beautiful church, are well worthy of an inspection by all true lovers of architecture, and reflect great credit, on the architect, Mr. R. J. Withers, of 51, Doughty street. The cost of these alterations has amounted to upwards of £1,000.

— Church Times, 26 May 1871, page 236

At the start of the 20th century the London County Council proposed to demolish the church to widen the Strand. A campaign involving the artist Walter Crane preserved the church itself; the graveyard was obliterated and the graves moved to Brookwood Cemetery. During the London Blitz of the Second World War the church was damaged by a nearby bomb explosion.^{[citation needed]}