The parish church is dedicated to the Holy Trinity and known as the "Cathedral of the Marshes".
Blythburgh was one of the earliest Christian sites in East Anglia.
There was a church there in 654 to which the bodies of the East Anglian king Anna and his son price Jurmin, descendants of King Wehha, were brought after their deaths in battle at Bulcamp with the Mercian king Penda.

At the time of the Norman Conquest Blythburgh was part of the royal estate and had one of the richest churches in Suffolk, possibly a Saxon minster, with two daughter churches.
It was probably the rich parent church that was granted by king Henry I to Augustinian canons some time between 1116 and 1147, becoming the priory of the Blessed Virgin Mary.
A daughter church is likely to have been the predecessor of Holy Trinity.
It was rebuilt in the 15th century.
In the movement to dissolve the monasteries, the suppression of Blythburgh Priory (which had its own conventual church) was authorised in 1528 and it was dissolved in 1537, the reversion of the property being granted to local gentleman Sir Arthur Hopton (1488-1555) in 1548.

The church underwent a series of disasters, man-made and natural.
The most dramatic of the latter variety came on 4 August 1577, when a storm hit the area, and during morning service lightning hit the church, "cleft the door, and returning to the steeple rent the timber, [and] brake the chimes".
The falling spire damaged the font and the roof,which wasn't repaired until 1782, destroying the angels in the west end bays.
The door shows marks, which have the appearance of burns caused by candle flames, which the credulous associate with the devil's fingerprints.
They have been associated with the 'Black Shuck' legend and this has been used as a title of a song by the Lowestoft rock group The Darkness which mentions Blythburgh in the lyrics.

During the 17th century Holy Trinity was badly damaged when Parliament set out to remove what the Puritans deemed to be superstitious ornamentation from churches; Blythburgh was assigned to William Dowsing, a local Puritan, and on 8 April 1644 he went to the church and ordered the removal of "twenty superstitious pictures, one on the outside of the church; two crosses, one on the porch and another on the steeple; and twenty cherubim to be taken down in the church and chancel... and gave order to take down above 200 more within eight days".

General neglect also played its part in the church's deterioration, resulting in part from rural poverty, and in part from the rise of Methodism – a Primitive Methodist chapel was founded in the village in the 1830s.

By the late 19th century the church was in a very poor state of repair, and in 1881 a restoration fund made possible the repair of the church, and then its maintenance after its reopening in 1884.
The restoration was controversial with William Morris and his Society for the Protection of Ancient Buildings opposed to the radical plans of the local building committee.
Shortage of funds restricted the work that could be done.
While the fabric was repaired, modern taste ruled out any return to the 15th-century colour scheme of the church; the thirty-six angels, set back to back in pairs on the arch-braced, firred, tie-beam roof had been brightly painted in red and green with much use made of tin foil and gold leaf.
A modern reproduction is mounted above the south door.

The church has a two-manual pipe organ by the company Bishop and Son, dating from 1951, which was almost completely rebuilt in 2003 by Rodney Briscoe.
A specification of the organ can be found on the National Pipe Organ Register.

In 1962 the acoustic value of the building was discovered by Benjamin Britten, and some of the concerts of the Aldeburgh Festival are performed in the church.

The church was the location of a 2011 music video for Sempiterna by Libera.
The parish church is dedicated to the Holy Trinity and known as the "Cathedral of the Marshes". Blythburgh was one of the earliest Christian sites in East Anglia. There was a church there in 654 to which the bodies of the East Anglian king Anna and his son price Jurmin, descendants of King Wehha, were brought after their deaths in battle at Bulcamp with the Mercian king Penda.
At the time of the Norman Conquest Blythburgh was part of the royal estate and had one of the richest churches in Suffolk, possibly a Saxon minster, with two daughter churches. It was probably the rich parent church that was granted by king Henry I to Augustinian canons some time between 1116 and 1147, becoming the priory of the Blessed Virgin Mary. A daughter church is likely to have been the predecessor of Holy Trinity. It was rebuilt in the 15th century. In the movement to dissolve the monasteries, the suppression of Blythburgh Priory (which had its own conventual church) was authorised in 1528 and it was dissolved in 1537, the reversion of the property being granted to local gentleman Sir Arthur Hopton (1488-1555) in 1548.
The church underwent a series of disasters, man-made and natural. The most dramatic of the latter variety came on 4 August 1577, when a storm hit the area, and during morning service lightning hit the church, "cleft the door, and returning to the steeple rent the timber, [and] brake the chimes". The falling spire damaged the font and the roof,which wasn't repaired until 1782, destroying the angels in the west end bays. The door shows marks, which have the appearance of burns caused by candle flames, which the credulous associate with the devil's fingerprints. They have been associated with the 'Black Shuck' legend and this has been used as a title of a song by the Lowestoft rock group The Darkness which mentions Blythburgh in the lyrics.
During the 17th century Holy Trinity was badly damaged when Parliament set out to remove what the Puritans deemed to be superstitious ornamentation from churches; Blythburgh was assigned to William Dowsing, a local Puritan, and on 8 April 1644 he went to the church and ordered the removal of "twenty superstitious pictures, one on the outside of the church; two crosses, one on the porch and another on the steeple; and twenty cherubim to be taken down in the church and chancel... and gave order to take down above 200 more within eight days".
General neglect also played its part in the church's deterioration, resulting in part from rural poverty, and in part from the rise of Methodism – a Primitive Methodist chapel was founded in the village in the 1830s.
By the late 19th century the church was in a very poor state of repair, and in 1881 a restoration fund made possible the repair of the church, and then its maintenance after its reopening in 1884. The restoration was controversial with William Morris and his Society for the Protection of Ancient Buildings opposed to the radical plans of the local building committee. Shortage of funds restricted the work that could be done. While the fabric was repaired, modern taste ruled out any return to the 15th-century colour scheme of the church; the thirty-six angels, set back to back in pairs on the arch-braced, firred, tie-beam roof had been brightly painted in red and green with much use made of tin foil and gold leaf. A modern reproduction is mounted above the south door.
The church has a two-manual pipe organ by the company Bishop and Son, dating from 1951, which was almost completely rebuilt in 2003 by Rodney Briscoe. A specification of the organ can be found on the National Pipe Organ Register.
In 1962 the acoustic value of the building was discovered by Benjamin Britten, and some of the concerts of the Aldeburgh Festival are performed in the church.
The church was the location of a 2011 music video for Sempiterna by Libera.
Holy Trinity Church, Blythburgh