Document and Entity Information - shares	3 Months Ended
	Sep. 30, 2023	Nov. 02, 2023
Document and Entity Information [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2023
Document Transition Report	false
Entity File Number	001-40255
Entity Registrant Name	WILLIAM PENN BANCORPORATION
Entity Incorporation, State or Country Code	MD
Entity Tax Identification Number	85-3898797
Entity Address, Address Line One	10 Canal Street
Entity Address, Address Line Two	Suite 104
Entity Address, City or Town	Bristol
Entity Address State Or Province	PA
Entity Address, Postal Zip Code	19007
City Area Code	267
Local Phone Number	540-8500
Title of 12(b) Security	Common Stock, par value $0.01 per share
Trading Symbol	WMPN
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		10,068,641
Entity Central Index Key	0001828376
Current Fiscal Year End Date	--06-30
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q1
Amendment Flag	false