I pretty sure this isn't possible, but it can't hurt to ask.

If a have a workbook that I populate from SQL Server every night with some business critical data. The file is in a location where people can link to it. I've been asked to add mucho info to it over the past few years, and I've lost track of who links to it and why. I'd like to audit the file to remove lines that aren't used. Is there any way to find the files that are linked to this one?

In Excel Help, type the word "link" in the Index tab. You should find something usable in the result topic window.

HTH,
Sam

Found this at microsoft.com

That applies to the linked workbook. That's why I think they didn't bother doing anything for a source workbook.

You might try the add-in: Findlink by Bill Manville (hosted on site by Stephen Bullen).

My first thought was to change the name of the file, then wait for the phone to ring when your users can no longer find or connect to it

You may want to try some of the other suggestions first.