Nope- it is its own self. Also known as cherry peppers, they are smaller and can range from sweet to spicy.
They are different, as many a southerner would tell you. BUT you can make your own pimientos with red bell pepper, and in most cases no one would be the wiser. My great-grandmother, who makes the entire family a big batch of pimiento cheese every week, boils her red bell peppers, but I prefer to roast mine under the broiler. Then remove the skin and chop.