How can I locate my disabled train stop among many stops with the same name?

Here's a not-so-elegant solution:

Rename all train stops with the same name to a new (but still shared) name. You can do this by adding the stop to a train's schedule, clicking the text to locate one of the stops on the map, and then rename it. Do this one by one. Sooner or later the sought-after stop will be the one that Factorio locates on the map for you.

It is crucial that you finish renaming all train stops even after you locate the one you want to find to not mess up your train scheduling.

Factorio 1.1 (November 23rd 2020) included an elegant solution for this: the Train Overview window. Here's the process:

1. Open the Train Overview with either the O key (by default) or clicking the train button above the mini map, second from the right (between the mortarboard and the trophy)
2. In the top left, be sure you're on the Stations tab, not the Trains tab
3. Select the desired station name on the left sidebar
4. Scroll through the tiles in the main panel, looking for an X-in-a-circle icon in the top right of the tile
5. Optional: mouse over the icon to see the reason for being disabled
6. Click on the mini map in the tile to go to that location on the map