COVER PAGE - shares	3 Months Ended
	Sep. 30, 2020	Nov. 02, 2020
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2020
Document Transition Report	false
Entity Registrant Name	OPEN TEXT CORP
Entity File Number	0-27544
Amendment Flag	false
Entity Central Index Key	0001002638
Current Fiscal Year End Date	--06-30
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Entity Incorporation, State or Country Code	Z4
Entity Tax Identification Number	98-0154400
Entity Address, Address Line One	275 Frank Tompa Drive,
Entity Address, City or Town	Waterloo,
Entity Address, State or Province	ON
Entity Address, Country	CA
Entity Address, Postal Zip Code	N2L 0A1
City Area Code	519
Local Phone Number	888-7111
Title of 12(b) Security	Common stock without par value
Trading Symbol	OTEX
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		272,375,498