Mine's 28.24%, but I never intend to carry a balance on it. I still use it regularly for many everyday expenses, as interest rate doesn't matter if I pay in full every month. This isn't uncommon, at least in my experience, for reward credit cards; as an example, my Chase Freedom Unlimited is at 27.99%. My credit score is quite solid (in the high 700s) and utilization is low, but I'm not sure if there's some other factor that throws me in a more expensive interest rate bucket.

I've very rarely seen a card, particularly one that's rewards-focused, with an APR below 19.99%. Some credit union cards (including a couple I have) are lower, but usually those are also ones that earn very little in the way of rewards. The tradeoff is usually lower rewards for a lower interest rate.