The Battle of Carlow took place in Carlow town, Ireland on 25 May 1798 when Carlow rebels rose in support of the 1798 rebellion which had begun the day before in County Kildare. The United Irishmen organisation in Carlow led by a young brogue-maker named Mick Heydon who had taken over the leadership following the arrest of the previous leader, Peter Ivers, who was arrested with several other leading United Irishmen at Oliver Bond's house in March of that year, had assembled on the night of the 24th and set off at dawn to attack the county town. Picking up more volunteers along the way, their numbers swelled to around 1,200 they marched completely unopposed.

An attack on the town would take place simultaneously from four different directions, through the four main streets.

1. From Bennekerry and Tinryland, an assault would be made into Tullow Street.

2. From Ballybar and Garryhundon, people would march in through Burrin Street.

3. From Laois, the attack would be across Graiguecullen bridge, over the Barrow and past the old Norman Castle crouching in the darkness.

4. From Palatine and Maganey, Dublin Street would be infiltrated.

All would converge on Potato Market.

As the various contingents advanced, they did not know that Colonel Mahon of the Ninth Dragoons had the military in the barracks and the town on the highest alert. Their every move was known to him. A strong party of military was stationed in the court house which is now known as the Deighton Hall (this is situated immediately to the north of the bridge across the river Burrin). Another party with two small cannon were stationed on the bridge. On Graigue bridge, there was an officer's guard of yeomen. In Dublin Street and to the north, well-armed loyalists filled some large strong houses, but without military support, as the attack was known to be weak from that quarter. Tullow Street was left open and to all appearances undefended against what was expected would be the strongest attack of all. The trap was laid.