| Cover | Apr. 27, 2022 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Apr. 27, 2022 |
| Entity File Number | 000-16106 |
| Entity Registrant Name | CLEARFIELD, INC. |
| Entity Central Index Key | 0000796505 |
| Entity Tax Identification Number | 41-1347235 |
| Entity Incorporation, State or Country Code | MN |
| Entity Address, Address Line One | 7050 Winnetka Avenue North, Suite 100 |
| Entity Address, City or Town | Brooklyn Park |
| Entity Address, State or Province | MN |
| Entity Address, Postal Zip Code | 55428 |
| City Area Code | 763 |
| Local Phone Number | 476-6866 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, $0.01 par value |
| Trading Symbol | CLFD |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
