轮状病毒（Rotavirus，简称RV）是一种双链核糖核酸病毒，属于呼肠孤病毒科。它是引起婴幼儿腹泻的最常见原因，几乎世界上小孩在大约五岁时都曾感染过轮状病毒至少一次。然而，每一次感染后人体免疫力会逐渐增强，因此之后再次感染的影响就会减轻，到成人阶段就很少受其影响。轮状病毒总共有八个种，以英文本母编号为A、B、C、D、E、F、G与H。其中，A种是最为常见的一种，超过90%人类轮状病毒感染是由该种造成。

轮状病毒是借由粪口途径传染的。它会感染与小肠壁上的肠黏膜细胞并且产生肠毒素（enterotoxin），肠毒素会引起肠胃炎，导致严重的腹泻，有时候甚至会因为脱水而导致死亡。虽然轮状病毒于1973年就被由澳洲的露丝·毕夏普所发现，而且造成婴儿与幼儿总计超过50%以上因为严重腹泻而住院治疗的案例，但是在公共卫生社区中它仍然没有被广泛地重视，特别是在发展中国家更是如此。除了对人类健康的影响之外，轮状病毒也会感染动物，是家畜的病原体之一。

Rotavirus is the most common cause of severe vomiting and diarrhoea among infants and young children. It is a genus of double-stranded RNA virus in the family Reoviridae. Nearly every child in the world has been infected with rotavirus at least once by the age of five. Immunity develops with each infection, so subsequent infections are less severe; adults are rarely affected. There are eight species of this virus, referred to as A, B, C, D, E, F, G and H. Rotavirus A, the most common species, causes more than 90% of rotavirus infections in humans.