Document and Entity Information - shares	9 Months Ended
	Mar. 31, 2021	May 07, 2021
Document And Entity Information
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Mar. 31, 2021
Entity Central Index Key	0000916907
Entity File Number	0-23406
Registrant Name	SOUTHERN MISSOURI BANCORP, INC.
Entity Incorporation, State or Country Code	MO
Tax Identification Number (TIN)	43-1665523
Entity Address, Address Line One	2991 Oak Grove Road
Entity Address, City or Town	Poplar Bluff
Entity Address, State or Province	MO
Entity Address, Postal Zip Code	63901
City Area Code	573
Local Phone Number	778-1800
Title of 12(b) Security	Common
Trading Symbol	SMBC
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		8,934,113
Current Fiscal Year End Date	--06-30
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Amendment Flag	false