斯里尼瓦瑟·拉马努金（泰米尔语：ஸ்ரீனிவாஸ ராமானுஜன் ஐயங்கார்，ISO 15919转写：Srīṉivāsa Rāmāṉujan Aiyaṅkār，又译拉马努詹，1887年12月22日－1920年4月26日）是印度历史上最著名的数学家之一。没受过正规的高等数学教育，沉迷数论，尤爱牵涉π、质数等数学常数的求和公式，以及整数分拆。惯以直觉（或跳步或称之为数感）导出公式，不喜作证明（事后往往证明他是对的）。他留下的那些没有证明的公式，引发了后来的大量研究。1997年，《拉马努金期刊》（Ramanujan Journal）创刊，用以发表有关「受到拉马努金影响的数学领域」的研究论文。2015年，他自学成才并负笈剑桥的传奇故事，被拍成电影《天才无限家》

Srinivasa Ramanujan FRS (pronunciation: /ʃriːnivɑːsə rɑːmɑːnʊdʒən/) (22 December 1887 –26 April 1920) was an Indian mathematician and autodidact. Though he had almost no formal training in pure mathematics, he made extraordinary contributions to mathematical analysis, number theory, infinite series, and continued fractions. Ramanujan initially developed his own mathematical research in isolation; it was quickly recognized by Indian mathematicians. When his skills became obvious and known to the wider mathematical community, centered in Europe at the time, he began a famous partnership with the English mathematician G. H. Hardy, who realized that Ramanujan had rediscovered previously known theorems in addition to producing new ones.