Applying to PhD programs; do I need to include transcripts from unrelated master's degree program? I'm interested in pursuing a PhD in a particular humanities field and I feel that my undergraduate GPA is strong enough for me to get into such a program at a top school. However, my path to deciding this has been somewhat circuitous. Along the way, I completed a master's degree in a completely unrelated subject which I became uninterested in and disillusioned by while I was in the program. I decided to complete it anyway and as a result of my lack of passion for the field, I didn't perform very well in my master's program and just did the minimum to complete my degree.

Now when I look at PhD applications, I see that every school's admission page says you must submit transcripts from all university level courses taken even though only a bachelor's degree is required for admission. My question is, if by omitting transcripts from my master's program, would I be violating most admission policies and/or risk having a misleading or unethical application?
"All university level courses taken" means "all university level courses taken", so yes, you should submit it too. Otherwise, if at any point they discover that you had been enrolled in that masters, you could be in trouble for lying.

Even if they don't require you to submit it, you will have to explain what were you doing during that time. And a bad master's is far better than sitting at home doing noting.

Now, you don't want it to hurt your application, so you should consider explaining in your cover letter why you did poorly. That shouldn't be too difficult, I think a good bachelor and a bad master is still better than just a good bachelor.