v3.25.1
Cover - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2024
May 30, 2025
Jun. 30, 2024
Document Information [Line Items]      
Document Type 10-K    
Document Annual Report true    
Document Transition Report false    
Document Financial Statement Error Correction [Flag] false    
Entity Interactive Data Current Yes    
ICFR Auditor Attestation Flag false    
Amendment Flag false    
Document Period End Date Dec. 31, 2024    
Document Fiscal Year Focus 2024    
Document Fiscal Period Focus FY    
Documents Incorporated by Reference [Text Block] None    
Entity Information [Line Items]      
Entity Registrant Name Onconetix, Inc.    
Entity Central Index Key 0001782107    
Entity File Number 001-41294    
Entity Tax Identification Number 81-2262816    
Entity Incorporation, State or Country Code DE    
Current Fiscal Year End Date --12-31    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Shell Company false    
Entity Filer Category Non-accelerated Filer    
Entity Small Business true    
Entity Emerging Growth Company true    
Entity Ex Transition Period false    
Entity Public Float     $ 3.6
Entity Contact Personnel [Line Items]      
Entity Address, Address Line One 201 E. Fifth Street    
Entity Address, Address Line Two Suite 1900    
Entity Address, City or Town Cincinnati    
Entity Address, State or Province OH    
Entity Address, Postal Zip Code 45202    
Entity Phone Fax Numbers [Line Items]      
City Area Code (513)    
Local Phone Number 620-4101    
Entity Listings [Line Items]      
Title of 12(b) Security Common stock, $0.00001 par value    
Trading Symbol ONCO    
Security Exchange Name NASDAQ    
Entity Common Stock, Shares Outstanding   44,358,422