I am 39 years old and just found I have a large ovarian cyst. I have major hip pain and its hard to walk. Could the cyst be the cause of my hip pain?

It may be the source. Of the pain but you should get it evaluated. An intrapelvic lesion like a large ovarian cyst can cause referred pains as can other problems within the pelvis or abdomen. Back problems and hip problems cannot be ruled out as can occasionally knee issues present that way as well. See an orthopaedic surgeon for an evaluation.
Possibly. Sometimes a cyst will compress a nerve in the pelvis with referred pain to the hip. A simple examination and x-ray of the hip will help to determine if the hip is the primary source of the pain. An MRI of the pelvis will help to delineate the exact position of the ovarian cyst.