The church consists of a simple nave and chancel with a projecting tower above the vestry (locked) in the north-west corner. It is mostly constructed of local whinstone with sandstone ashlar dressings; the roof is of Welsh slate.
Most of the present building dates from 1849 when the church was rebuilt in the neo-Norman style by the architects Bonomi and Cory of Durham. The oldest parts of the church are the 12th century chancel arch (rebuilt in the 13th century in the pointed form) and some areas of walling at a low level.
The Parish of Branxton, although small in area and with a tiny population, has supported a church from at least the 12th century and possibly earlier. Little is known of the building prior to its rebuilding in 1849. In 1725 it was recorded that ‘the church is in a sad condition’ and an 1823 sketch plan shows a church with a nave broader than the present one. The Rev. Robert Jones, who was vicar of the parish from 1834 – 1870, was instrumental in the rebuilding of the church.
Local tradition has it that the church’s dedication should be to St Paulinus, who spread the Christian faith in the Glendale area in the 7th century, rather than St Paul. Towards the end of the 12th century Ralph, son of Gilbert of Branxton, gave the church to the monks of Durham in a grant confirmed by the king in 1195. It is likely that the church would have suffered in the long running border wars between the Scots and the English that culminated with the tragic battle of Flodden.
Since the rebuilding of the church in the 19th century there have been a few alterations. Early in the 20th century the entrance door in the south wall was moved to its west end and the present porch built and at the same time an additional window added in the south wall. The memorial windows in thewest wall were added soon after the end of the 1914-18 War and in 2013 the Flodden memorial doors between the porch and the nave were added.
In the porch there is a board naming the villagers who enlisted in the armed forces during the 1st World War; the stone tablet on the west wall records those who died and the stained glass memorial windows above depict the regimental insignia of the fallen. The external oak door to the porch was gifted in memory of the owner of the nearby Pallinsburn estate who died of wounds from the Korean War (1950-53).
The glazed ‘Go in Peace’ Flodden memorial doors were made by Taylor and Green of Etal and uses local oak gifted by the Pallinsburn estate. The glass panels were designed, and then engraved in situ, by Philip Lawson Johnston. One panel depicts a Scots Pine and the other an English Oak; a river appears in both panels intrinsically linking Scotland and England from the pine to the oak; in the foreground is a plough and pruning hook. This is to symbolise the reconciliation between the former warring nations of 1513 and the biblical reference “and they shall beat their swords into plough shares, and their spears into pruning hooks: nation shall not lift up sword against nation, neither shall they learn war anymore."