What specific degree is needed to become a writing editor?
But - many likely come with an English background. You might google the term + linkedin and see what pops up.
But nothing is required and I’m sure editors come from many fields. A business publication may have a business degree. Many writers are ex business people or ex engineers or may have degrees in poli sci or otherwise.
What they do have is the knack and skill set to do the job - and they’ve clearly written plenty in the past.
I don’t know but I’d imagine English is probably the most common major or perhaps a print journalist.
But your question is opaque - because an editor for what type of writing?