| Themelios | |
| Cover: | Themelios.jpg |
| Discipline: | Religious studies |
| Abbreviation: | Themelios |
| Editor: | Brian J. Tabb |
| Frequency: | Triannually |
| Website: | https://www.thegospelcoalition.org/themelios/ |
| Publisher: | The Gospel Coalition |
| History: | 1962-present |
Themelios (Greek: Θεμέλιος, i.e., foundation or keystone) is a peer-reviewed international evangelical theological journal that expounds on the historic Christian faith. Its primary audience is theological students, pastors and scholars. It was formerly a print journal operated by RTSF/UCCF in the UK, and it became a digital journal operated by The Gospel Coalition in 2008. Also previously it was known as the Theological Students Fellowship (TSF) Bulletin from 1951 to 1957.