Document and Entity Information - shares	3 Months Ended
	Dec. 31, 2018	Feb. 14, 2019
Document and Entity Information [Abstract]
Entity Registrant Name	DEEP WELL OIL & GAS INC
Entity Central Index Key	0000869495
Trading Symbol	DWOG
Amendment Flag	false
Current Fiscal Year End Date	--09-30
Document Type	10-Q
Document Period End Date	Dec. 31, 2018
Document Fiscal Period Focus	Q1
Document Fiscal Year Focus	2019
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Common Stock Shares Outstanding		230,574,603