| Document and Entity Information | Apr. 30, 2024 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Apr. 30, 2024 |
| Entity File Number | 001-38427 |
| Entity Registrant Name | PIEDMONT LITHIUM INC. |
| Entity Central Index Key | 0001728205 |
| Entity Incorporation, State or Country Code | DE |
| Entity Tax Identification Number | 36-4996461 |
| Entity Address, Address Line One | 42 E Catawba Street |
| Entity Address, City or Town | Belmont |
| Entity Address, State or Province | NC |
| Entity Address, Postal Zip Code | 28012 |
| City Area Code | 704 |
| Local Phone Number | 461-8000 |
| Title of 12(b) Security | Common Stock, $0.0001 par value per share |
| Trading Symbol | PLL |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
