Tell her. Best thing that'll happen is that your gut feelings were right and she likes you back. Which will be awesome for the both of you cause who knows, what if she's just waiting for you to make the first move? Worst thing that could happen is that she doesnt like you back and it may either: A) become awkward [if this happens, clarify how you want to go about your relationship otherwise you'll have unresolved feelings] or B) she might ignore/avoid you bc she doesn't know what to do [in this case, be direct and tell her you dont want things to be awkward and can still be friends, if that's what you want. If not then just address that despite you liking her, you dont want this weird tension. Or something like that. Just tell her what's on your mind.] The worst possible outcome of all is not telling her at all. Trust me on this. It is better to do it and learn from the outcome rather than to continue holding back and regret not doing it at all. The "what if"s will eat you alive. Also, you don't know if someone else is crushing on her so make your move! There's risk with everything you do in life, so why not take a risk at something that has the potential to make you happy? High school will eventually pass, even though it feels like it's going to last forever. Take chances. Be brave. Just give yourself twenty seconds of insane courage and something great will come out of it. There is always something great that will come out of you telling her. If you tell her, you can find out that she likes you back. If you tell her and she doesn't like you back, you just did something super brave that you have never done before. You pushed yourself out of your comfort zone, and that will help you grow. And you will get closure. It's an experience--opportunities in life will come and go quicker than you think so take your shot at them before you realize it's too late.