Is it OK to leave a job off my resume completely?

Yes. A resume is a selection of your most relevant experience, not a full legal record of every job, so leaving out a short or unrelated job is normal.

Before you remove a job, check two things:

• Does removing it leave a noticeable gap? If so, a one-line entry may look better than an unexplained space.
• Does the employer's application form ask for your complete employment history? Some forms and background checks do. In that case, list every job on the form as asked, even if your resume is shorter.

Leaving something off is different from changing facts. Never stretch the dates of other jobs to cover the space where the removed job was. If someone asks about the period, answer honestly and briefly.