Changing labels language on XYZ tiles using QGIS?

That's not because of your locale. Open Street Map uses Hebrew labels in Israel by default. According to the OSM Wiki there's no web feature service of OSM data, so you're stuck using pre-generated tile sets. As far as I can tell, OSM doesn't have a tile server with English-only labels.

You can add English labels to your map in this way:

  1. Use the Quick OSM plugin to download street lines for your area of interest.
  2. Style the street lines with no symbology, label using using the field "name:en".
  3. Repeat as needed for other features such as towns, railways, etc.

These labels will sit on top of your existing base map. With the standard OSM base map you'll see Hebrew and English labels. QGIS can't tell where the labels are in the basemap, so the English labels may overlap the Hebrew ones.

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You can try various other base maps.

To get other base maps, install the plugin QuickMapServices, open the plugins Settings, and under "more services" choose the option to "get contributed pack." Some have labels in English. Others have no labels at all, which will allow you to see only the labels that you put on the map.

Here are a few examples that may be useful:

  • Google Roads uses English labels, if you're willing to tolerate the addition of various businesses to the map.

  • ESRI Standard uses a combination of English and Hebrew labels.

  • Bing Map uses mostly English labels

  • CartoDB Dark Matter and Positron are available with no-label versions

IMPORTANT: Before publishing a map, be sure to read the terms and conditions for the basemap to make sure you're allowed to use that basemap for your project. Many require a particular attribution.

  • OSM Tile Usage Policies
  • List of tile services based on OSM, including links to terms of use for each service

Per the suggestion from @scai, wikimedia.org provides base maps where the labels are all in one language. The English-language base map can be found here: https://maps.wikimedia.org/?lang=en

Also see this list of tile servers that provide multilingual tiles: https://wiki.openstreetmap.org/wiki/Map_internationalization#Tile_servers