It was founded in the 12th century and is still a working church with a cafe, Play Area and Exhibition Space open during the week.

[3] It retains over one hundred and fifty brasses and monuments, the oldest dating from 1436, though all that now remains of the original Norman church is some pillar bases and the chisel marks on them.

In 1876, the galleries were 'thrown back' from the nave pillars (i.e. reduced in width by one half), an older plaster ceiling was removed and a roof of stained wood installed.

On 4 October 1940 the south aisle roof was destroyed by incendiary bomb and the gallery on that side was subsequently demolished to provide timber for repairing the church.

During the spring of 1942 all the railings surrounding the churchyard and most of those round the monuments were removed to provide scrap iron help the war effort.

Post-war restoration of the church included a new heating system (with a boiler house built outside the north porch) and the rebuilding of the organ.

In 2016, a major project was launched to restore the 10 church bells so that they are able to be rung for at least another 100 years and future generations can enjoy them.

The regeneration project repaired and renovated the ancient building to make it more suitable for community arts and cultural activities, alongside securing its future as a working parish church.

[6] The churchyard is home to the Burials in Bloom project, where local residents "adopt" a grave that is not currently visited.

[8] St Mary's is an active church today, with a large congregation involved in supporting the local community.

The church hosts regular exhibitions, performances and other community events, and has a cafe run by local partners Ruttle & Rowe with both indoor and outdoor seating as well as a Play Area for young children.

[10] In addition to being known for its ancient building and community involvement, St Mary's is also well known for its churchyard, which is the largest green space in Walthamstow Village and which won 'Churchyard of the Year' in the 2023 London in Bloom gardening competition.