Of course, anticipate the "Tell me about yourself" question.
Definitely be able to distinguish OT vs PT vs Speech. (don't say OT does upper extremities and PT does lower extremities!! lol)
Strengths and weaknesses.
Be prepared for ethical questions and other situational type questions- conflict, group dynamics, etc.
Why do you want to be an OT?
How might your educational background or other experiences contribute to your success in graduate study?
Cultural questions- how do you handle diversity?
Be able to articulate what you saw in your observations and maybe what stood out to you or aspects that interested you.
How would you describe OT for a friend?
How will graduate study be different than undergrad?
Why do you want to attend this program? (make sure you do your research about the program, mission, values, etc.)
Why do you think you'll make a good OT?
What qualities should an OT have?
In one of my interviews, I actually had to act out an intervention.
An interesting interview question was a situational question where I was asked if I had a patient enter rehab from the hospital setting and had to do an eval that day, what would I look at first (bathing, grooming, or dressing) and why?--I think they are looking for your ability to critically reason in questions like that. There wasn't necessarily a right or wrong answer from what they told me.
Maybe reflect on some of your leadership skills and experiences you had where you demonstrated these skills.
If community service is important to this program, definitely articulate how you have participated in community service.
And of course, be confident. Smile. Treat the interview like a conservation rather than something rehearsed.
Use the interview as an opportunity to shine and show your passion about OT. I hope this helps.
Good luck!!