| Cover Page - USD ($) $ in Millions | 12 Months Ended | | |
| Dec. 31, 2022 | Mar. 20, 2023 | Jun. 30, 2022 |
| Cover [Abstract] | | | |
| Document Type | 10-K/A | | |
| Amendment Flag | true | | |
| Document Period End Date | Dec. 31, 2022 | | |
| Document Fiscal Year Focus | 2022 | | |
| Document Fiscal Period Focus | FY | | |
| Entity Registrant Name | ONCORUS, INC. | | |
| Current Fiscal Year End Date | --12-31 | | |
| Entity Central Index Key | 0001671818 | | |
| Entity Well-known Seasoned Issuer | No | | |
| Entity Current Reporting Status | Yes | | |
| Entity Voluntary Filers | No | | |
| Entity Small Business | true | | |
| Entity Emerging Growth Company | true | | |
| Entity Ex Transition Period | false | | |
| Entity Shell Company | false | | |
| Entity Filer Category | Non-accelerated Filer | | |
| Entity File Number | 001-39575 | | |
| Entity Address, Address Line One | 4 Corporate Drive | | |
| Entity Address, City or Town | Andover | | |
| Entity Address, State or Province | MA | | |
| Entity Tax Identification Number | 47-3779757 | | |
| Entity Address, Postal Zip Code | 01810 | | |
| Entity Incorporation, State or Country Code | DE | | |
| City Area Code | 339 | | |
| Local Phone Number | 240-3330 | | |
| Document Annual Report | true | | |
| Document Transition Report | false | | |
| Entity Interactive Data Current | Yes | | |
| Entity Common Stock, Shares Outstanding | | 26,095,363 | |
| Entity Public Float | | | $ 25.9 |
| Security Exchange Name | NASDAQ | | |
| Trading Symbol | ONCR | | |
| Title of 12(b) Security | Common Stock, $0.0001 par value per share | | |
| ICFR Auditor Attestation Flag | false | | |
| Amendment Description | Oncorus, Inc. (the "Company," "Oncorus," "our," "us" or "we") is filing this Amendment No. 1 (this “Amendment”) to our Annual Report on Form 10-K for the fiscal year ended December 31, 2022 (the "Original Report"), filed with the U.S. Securities and Exchange Commission (the “SEC”) on March 24, 2023. We are filing this Amendment to provide the information required by Part III of Form 10-K that was omitted from the Original Report in reliance on General Instruction G(3) to Form 10-K. In addition, as required by Section 302 of the Sarbanes-Oxley Act of 2002 and Rule 12b-15 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), updated certifications of our principal executive officer and principal financial officer are included as Exhibits 31.1 and 31.2 hereto. Because no financial statements have been included in this Amendment and this Amendment does not contain or amend any disclosure with respect to Items 307 and 308 of Regulation S-K, paragraphs 3, 4, and 5 of the certifications have been omitted. We are not including the certifications under Section 906 of the Sarbanes-Oxley Act of 2002 as no financial statements are being filed with this Amendment. No other changes have been made to the Original Report other than those described above. This Amendment does not reflect subsequent events occurring after the filing date of the Original or modify or update in any way the financial statements, consents or any other items or disclosures made in the Original Report in any way other than as required to reflect the amendments discussed above. Accordingly, this Amendment should be read in conjunction with the Original Report and our other filings with the SEC subsequent to the filing of the Original Report. | | |
| Documents Incorporated by Reference | DOCUMENTS INCORPORATED BY REFERENCE None. | | |
| Auditor Name | Ernst & Young LLP | | |
| Auditor Location | Boston, Massachusetts | | |
| Auditor Firm ID | 42 | | |
