Digital Humanities (DH) positions itself as an inherently international endeavour, yet the extent to which its citation practices reflect this aspiration remains largely untested at scale. We present a bibliometric analysis of geographic citation insularity — the tendency of scholars to cite works produced in their own country — across the DH field from 2007 to 2025. Using OpenAlex, we constructed a corpus of approximately 17,600 DH works by combining publications from 19 exclusively DH journals (following Spinaci et al. 2022) with keyword-matched works. We extracted 58,655 citation-level records with country metadata for both citing and cited works, covering 63 countries. We find that 28% of DH citations are geographically insular, and that every country with sufficient data cites itself significantly more than a null model based on publication shares would predict. However, the pattern is not uniform: smaller national communities such as Finland, Austria, and Greece exhibit insularity ratios up to 31 times their expected baseline, while larger producers like the US and UK show lower ratios despite higher absolute self-citation. We also document a clear temporal decline, from roughly 40% insularity in 2007–2009 to 27% in 2022–2025, suggesting that DH citation networks are gradually internationalizing. These findings confirm longstanding qualitative critiques of geographic bias in DH while offering a more nuanced picture: insularity is universal but declining, and most pronounced in smaller, cohesive national communities rather than in the Anglophone centres that dominate overall output.