Naseby is most well-known for its associations with the English Civil War. It was here on June 14, 1645, that one of the most important battles of the war was fought. A Parliamentary army under the command of Thomas Fairfax confronted Royal troops led by King Charles but commanded in the field by the king's nephew, Prince Rupert.

At first the royal army had the upper hand, but Fairfax's cavalry, headed by Oliver Cromwell, swung the tide of battle, and the royalists were routed. Parliament's total victory at Naseby effectively ended the Civil War, though the king dragged matters out until 1646. As a curious side-note, the parish register at Naseby makes no mention at all of the great battle which bears its name.

Today the battlefield can best be approached via the Sibbertoft road, where a Battlefield Monument marks the spot where Cromwell's cavalry began the engagement. Interpretive panels outline the course of the battle. A second monument stands on the Clipston road on the northern approaches to the village, with another interpretive panel explaining the battle and its consequences.

The name "Naseby" has its origins in the Dark Ages when it was known as "Hnaefes-Burh", or "fortified place of Hnaefe", Hnaefe being the name of a Saxon settler.

Naseby was a thriving market town in the early Middle Ages, with a market charter granted by King John in 1203. However, the Black Death of 1349 took a terrible toll on the town, and the population dwindled dramatically. Nearby fields still show traces of abandoned buildings from this period.

All Saints church at Naseby has roots dating back to the Saxon period, and there may have been a Christian settlement here as early as 620. The present church dates from the early 13th century. The South aisle was added to the Saxon church in 1232, and the present nave and North aisle added over the next 75 years. In the 15th century the walls of the church were raised and a clerestory, low tower, and spire added. A new spire was built in 1860, from which it is said that The Wash and the towers of 40 churches can be seen on a clear day.

A curious remnant of Naseby's history can be found leaning against the outer wall of the North Aisle. It is "Cromwell's Table", which originally graced Shuckborough House, just opposite the church. The story goes that on the eve of the Battle of Naseby some of the king's lifeguards were sitting down to supper at the table when they were suprised by Cromwell's troops. Several of the royal soldiers were killed, and the rest captured. Their duty done, Cromwell's men sat down at the table and finished the meal!

In the grounds of Manor House on Newlands is the origin of the spring which gives rise to Shakespeare's River Avon. On Church Street is the remnant of the 13th century market cross, a memento of those halcyon days before the Black Death came calling in Naseby.