Document and Entity Information - USD ($)
12 Months Ended
Mar. 31, 2018
Jun. 04, 2018
Sep. 30, 2017
Document and Entity Information      
Entity Registrant Name Myovant Sciences Ltd.    
Entity Central Index Key 0001679082    
Document Type 10-K    
Document Period End Date Mar. 31, 2018    
Amendment Flag false    
Current Fiscal Year End Date --03-31    
Entity Current Reporting Status Yes    
Entity Filer Category Accelerated Filer    
Entity Common Stock, Shares Outstanding   64,875,000  
Document Fiscal Year Focus 2018    
Document Fiscal Period Focus FY    
Entity Public Float     $ 339,112,069
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No