First-Class Fastest Centuries by Balls (where recorded) in Ireland

Balls
51	NJ Maddinson	Australia A v Ireland	Civil Service Cricket Club, Stormont, Belfast	2013
110	PR Stirling	Ireland v Australia A	Civil Service Cricket Club, Stormont, Belfast	2013
124	Simranjit Singh	Leinster Lightning v Northern Knights	The Village, Malahide, Dublin	2019
129	JNK Shannon	Northern Knights v Leinster Lightning	Civil Service Cricket Club, Stormont, Belfast	2017
131	AR White	Ireland v Canada	The Village, Malahide, Dublin	2008
135	EC Joyce	Ireland v United Arab Emirates	The Village, Malahide, Dublin	2015
136	Nizakat Khan	Hong Kong v Ireland	Civil Service Cricket Club, Stormont, Belfast	2016
139	MP O'Dowd	Netherlands v Ireland	The Village, Malahide, Dublin	2017
147	JP Bray	Ireland v Netherlands	Civil Service Cricket Club, Stormont, Belfast	2005
147	PR Stirling	Ireland v United Arab Emirates	The Village, Malahide, Dublin	2015
148	EC Joyce	Leinster Lightning v Northern Knights	Castle Avenue, Dublin	2017
152	HT Tector	Northern Knights v Leinster Lightning	The Village, Malahide, Dublin	2019
152	LJ Tucker	Raiders v Strikers	The Village, Malahide, Dublin	2024
164	SPD Smith	Australia A v Ireland	Civil Service Cricket Club, Stormont, Belfast	2013
176	A Balbirnie	Ireland v Netherlands	The Village, Malahide, Dublin	2017
186	KJ O'Brien	Ireland v Pakistan	The Village, Malahide, Dublin	2018
187	AR White	Ireland v Namibia	Civil Service Cricket Club, Stormont, Belfast	2011
258	JF Short	Ireland v Scotland	Observatory Lane, Rathmines, Dublin	1975

The list shows 18 occurrences of 258 or less