St Matthais Old Church is the modern name given to the Poplar Chapel built by the East India Company in 1654.

In 1627 the East India Company (EIC) purchased a house in Poplar High Street to be used as a hospital for disabled seamen. In 1618 a corrupt jeweller, Hugh Greete, had been sent back from India for stealing some of the best stones. He died in prison in 1619, however he directed that a school or hospital be founded from his estate. The Company had set up a shipyard in Blackwall in 1614, so neighbouring Poplar was the obvious choice for location. In 1633 the inhabitants of Poplar and Blackwall - largely employees of the EIC - requested that a chapel be built there as St Dunstans, Stepney was too far away for them. When Gilbert Dethick, the Lord of the Manor of Poplar, died in 1639 he left a further £100 towards the building of the chapel, if work started within three years of his death.

The beginning of the work coincided with the outbreak of the English Civil War. William Laud, the Archbishop of Canterbury was executed in 1645 after being prominently involved in debates about church architecture and internal decour. With a further bequest from Sir John Gayer, a director of the EIC, and money direct from the Company meant that work eventually got properly underway in 1652 - the first instalment was paid to John Tanner, Master of the Bricklayers' Company in 1654, who became the principal builder. St Matthais Old Church is one of only three extant commonwealth churches (the others are the Holy Trinity Church, Berwick on Tweed and the church in Staunton Harold, Leicester built by Sir Robert Shirley a Royalist baron). It was a brick building enhanced with stone quoins at the corners. It combines both Classical and Gothic elements, similar to St Katherine Kree consecrated in the City of London in 1631 Internally the roof is supported by eight Tuscan columns, seven made of oak and one of stone. There is no evidence to support the story that they were made from ships' masts. They support a barrel-vaulted roof. All of this gives a Dutch flavour to the architecture reminiscent of Hendrick de Keyser who built several churches in Amsterdam in the early seventeenth century.

During the eighteenth century various changes were made, a tower added (1718), a triple-decker pulpit (1733) and extensive repairs and alterations to the windows in 1775 - 1776. In the early nineteenthcentury a mural monument to George Steevens by John Flaxman. This is currently on loan to the Fitzwilliam Museum, Cambridge.

For many years the Chapel was used for prayers before mariners and passengers departed on perhaps a dangerous voyage. many early migrants to North America would have participated in these services before leaving for an uncertain future abroad. It was also the chapel of the Poplar Pensioners who lived in adjacent almshouses. These pensioners were all former seamen who had worked for the EIC. Officers had premises up by the East India Dock Road, whereas the other ranks were located on Poplar High Street.

Following the First Indian War of Independence, the EIC was wound up and Poplar Chapel became St Matthais, an Anglican Parish Church. William Milford Teulon carried out substantial changes from 1867 to 1876: a modern pulpit, font and organ were installed, the building was clad in Kentish ragstone and a chancel, vestry and organ chamber were installed. Stain glass windows incorporating masonic imagery were installed, and indeed the church was regularly used by East London lodges.

Poplar was heavily bombed during the Second World War, but St Matthais survived with only shards of shrapnel buried in some of the walls. However in the 1970s dwindling congregations led to a mergers and the church was declared redundant in 1977. After several years of dereliction English Heritage and the London Docklands Development Corporation agreed to major restoration in 1990. In 1992 the St Matthais Conservation trust was set up to preserve the building and provide use as a community centre.