St Nicholas’ church is the oldest building in the parish, with the chancel, nave and south aisle dating to the early 13th century. As the village was a settlement for centuries prior to this, it is very likely that a church existed on the site even before St Nicholas’ was built. The south aisle and chancel were rebuilt in the fourteenth century and the tower added in the fifteenth century, along with a number of windows. The church underwent restoration in 1830 at which point it is likely the south porch was added.
A further restoration in 1889 discovered beneath a crust of whitewash, a large series of medieval paintings on the north wall of the nave, They still can be seen and appreciated today. It is thought the paintings were painted one on top of the other over the 13th, 14th and 15th centuries. In the 1925 book A History of the County of Buckinghamshire: Volume 3 when it is likely the paintings were more visible than they are today, it states:
Of the earliest, which is apparently of 13th-century date, only a small part is visible, and this seems to represent two episodes in the life of St. Nicholas. The eastern subject shows three mail-clad figures, one with a spear, entering a building, and perhaps illustrates the legend of the three knights claiming the hands of the daughters of a nobleman who had, in answer to the prayer of St. Nicholas, each received a bag of gold, and thus been saved from an immoral life. The western scene consists of two figures, a third being evidently hidden by the later work, emerging from a tub, on the west of which is the figure of a bishop, and on the east another figure. This probably represents the legend of the miraculous restoration to life of the three murdered students.
Very little is now decipherable of the second series of paintings, which seem to date from the middle of the 14th century; a small part of a figure in armour and the lower limbs of a second figure can, however, still be traced. The latest series is the most complete and interesting of the three, and probably dates from about 1500. It includes three subjects, the eastern of which is rather indistinct, but represents the legend of St. Christopher. To the west of this is a large representation of the purging of the Seven Deadly Sins; it comprises a large nude figure, around which are portrayed the several sins connected to it by a series of scrolls. Above this painting is another part of the third series, which is, however, now indecipherable. Another large painting was discovered on this wall further towards the east, but was unfortunately not preserved.
The village has enjoyed the sound of the bells at St Nicholas since 1552 and a new ring of five were cast in 1672 with two of the original ring still in situ. The remaining three bells were recast in 1793, 1895 and 1934 respectively. However the bell frame was badly decayed and resulted in the bells not being able to be rung for a number of years in recent times. To rectify this, the village community came together to raise funds over a number of years to replace the frame, refurbish the bells and add a new one. A huge project was undertaken to remove the bells and frame and there was much excitement in the village when the new frame and bells were delivered and refitted in 2021. The bells now ring out weekly for bellringing practice as well as on key community occasions and when bellringers visit from other towers.
The church features many stained glass windows and in 1953 a new window was donated by a village resident to commemorate her husband, Michael Dewar and his role in importing Sherman tanks to Britain during the Second World War. Judith and Michael Dewar lived in Little Horwood Manor from after the war until 1950 when he passed away.
After the Second World War, Robert Britten, brother of Benjamin, taught at the Old Ryde School (now Horwood House) and became the organist at the church and started the village choir of choristers.
The line of vicars at St Nicholas is recorded and dates back to Roberto de Horwode in 1275, with the current vicar being Rev Yvonne Mullins. Today, the church is part of the Five Parishes made up of the Benefice of Newton Longville, Mursley, Swanbourne, Little Horwood, and Drayton Parslow within the Diocese of Oxford.