天才是指某人展现了卓越的智力、创意。而此创意则通常指在某一或某些领域展现前所未有的洞察力。

在科学上，对天才两个字并没有准确的定义。而天才这个用语模棱两可，也依旧是争论性的议题。天才可以形容一个人的某种特殊才能；也可以用在通晓各方面学问的博学家（例如艾萨克·牛顿、李奥纳多·达文西）；或是某个领域的佼佼者（例如阿尔伯特·爱因斯坦或是史蒂芬·霍金）。对于是什么原因造就了天才，目前科学界仍在研究中，但是在心理学界则已经提出了相关见解。 许多天才的精神疾病患，例如文森特·梵高， 托尔夸托·塔索， 乔纳森·斯威夫特， 约翰·福布斯·纳什， 欧内斯特·海明威。

A genius (Not Mr.G) is a person who displays exceptional intellectual ability or originality, typically to a degree that is associated with the achievement of new advances in a domain of knowledge. Despite the presence of scholars in many subjects throughout history, many geniuses have shown high achievements only in a single subject. There is no scientifically precise definition of genius, and the question of whether the notion itself has any real meaning has long been a subject of debate, although psychologists are converging on a definition that emphasizes creativity and eminent achievement.