| Document and Entity Information | Dec. 16, 2020 |
| Document and Entity Information [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Dec. 16, 2020 |
| Entity File Number | 001-38520 |
| Entity Registrant Name | MeiraGTx Holdings plc |
| Entity Incorporation, State or Country Code | E9 |
| Entity Tax Identification Number | 98-1448305 |
| Entity Address, Address Line One | 450 East 29th Street |
| Entity Address, Adress Line Two | 14th Floor |
| Entity Address, City or Town | New York |
| Entity Address, State or Province | NY |
| Entity Address, Postal Zip Code | 10016 |
| City Area Code | 646 |
| Local Phone Number | 860-7985 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Ordinary Shares, $0.00003881 par value per share |
| Trading Symbol | MGTX |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | false |
| Entity Central Index Key | 0001735438 |
| Amendment Flag | false |
