Document and Entity Information - shares	9 Months Ended
	Jun. 30, 2019	Aug. 14, 2019
Document and Entity Information [Abstract]
Entity Registrant Name	DEEP WELL OIL & GAS INC
Entity Central Index Key	0000869495
Amendment Flag	false
Current Fiscal Year End Date	--09-30
Document Type	10-Q
Document Period End Date	Jun. 30, 2019
Document Fiscal Period Focus	Q3
Document Fiscal Year Focus	2019
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Shell Company	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Common Stock Shares Outstanding		230,574,603
Entity File Number	0-24012
Entity Interactive Data Current	Yes
Entity Incorporation State Country Code	NV