A thigh-high boot is a really long shoe that comes all the way up to your thigh! It's like wearing pants and shoes all together! You can wear it on your foot just like a regular shoe, but it goes up higher on your leg. People like to wear thigh-high boots because it keeps their legs really warm and it looks stylish too! Sometimes people wear them with a dress or skirt, and other times they wear them with pants. So next time you see a person wearing really long shoes, just know that they're wearing thigh-high boots!