| Document And Entity Information | Jun. 15, 2021 |
| Document Information [Line Items] | |
| Entity, Registrant Name | Oak Valley Bancorp |
| Document, Type | 8-K |
| Document, Period End Date | Jun. 15, 2021 |
| Entity, Incorporation, State or Country Code | CA |
| Entity, File Number | 001-34142 |
| Entity, Tax Identification Number | 26-2326676 |
| Entity, Address, Address Line One | 125 N. Third Ave |
| Entity, Address, City or Town | Oakdale |
| Entity, Address, State or Province | CA |
| Entity, Address, Postal Zip Code | 95361 |
| City Area Code | 209 |
| Local Phone Number | 848-2265 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock |
| Trading Symbol | OVLY |
| Security Exchange Name | NASDAQ |
| Entity, Emerging Growth Company | false |
| Amendment Flag | false |
| Entity, Central Index Key | 0001431567 |
