Should a degree in an unrelated field be included in CV?
While there are some circumstances in which is it appropriate to use a "shortened" C.V. that does not include everything that you have done, I have never heard of a circumstance under which it is appropriate to omit a degree.  An irrelevant degree will not hurt how your C.V. is perceived, and if it is later discovered that you omitted a degree from your C.V., it may be considered suspicious or dishonest.  Furthermore, it may under some circumstances be considered a plus---you never know what kind of interesting cross-disciplinary connections somebody reading your C.V. might make in their head. I would thus advise you to include all of your degrees, even if some seem irrelevant to you.