There is no known portrait that has ever been positively identified as being Kathryn Howard. Both images below have been said to be Henry VIII's fifth Queen. It is quite possible that all paintings (if any were made) were destroyed after Kathryn's execution. In fact, little other momentos of her short reign survive to this day.

This miniature was identified at Kathryn Howard in the 1840s, but that has never been confirmed. Some reserachers are now beginning to think that this may in fact be Kathryn, based on the fact that she is wearing jewelry that had belonged to Jane Seymour. The jewelry would have been part of the 'Queen's Jewels' which means that after Jane's death, they probably would have gone back to the king and then passed on to his future wives. [One problem to this theory is that the colors of the stones don't quite appear to be the same in each painting. However, one was a miniature, and one was a full-sized portrait, which could perhaps account for some of the variations.]