热带气旋警告信号（英语：Tropical cyclone warnings and watches）是指全球各处常常受热带气旋影响的地区，于风暴侵袭时发出的警告信号。用以通知当地居民及民防组织采取适当的防御或撤离措施。这些警告涉及警告范围内可能遭受的灾害，而不是单纯重复热带气旋的预测路径及强度，对于保障人命及财产安全尤为重要。在港、澳地区，警告信号强度在过去几十年内，沿用1至10不等的数字表示，并惯称作「风球」；例如在七十年代初，电台会发布「五号（八号西北）风球现正悬挂」等广播消息。而在中国大陆，早期分为“台风消息”（表示西北太平洋洋面上有热带气旋向沿海移动并可能在两三日内吹阵风烈风），“台风警报”（预计36小时内会吹阵风烈风），以及“台风紧急警报”（在未来24小时前后将吹暴风以上的持续风力，并将对沿海产生严重影响），同时在沿海港口和渔村悬挂风球。九十年代后开始采用1-5级的警告信号，在2006年再度更换为台风蓝、黄、橙、红预警信号，广东省则有白色的预警信号。

Tropical cyclone warnings and watches are two levels of alert issued by national weather forecasting bodies to coastal areas threatened by the imminent approach of a tropical cyclone of tropical storm or hurricane intensity. They are notices to the local population and civil authorities to make appropriate preparation for the cyclone, including evacuation of vulnerable areas where necessary. It is important that interests throughout the area of an alert make preparations to protect life and property, and do not disregard it on the strength of the detailed forecast track. Tropical cyclones are not points, and forecasting their track remains an uncertain science.