| Manuel Dias | |
| Birth Date: | 1574 |
| Birth Place: | Castelo Branco, Portugal |
| Death Date: | 4 March 1659 |
| Death Place: | China |
| Nationality: | Portuguese |
| Occupation: | Jesuit missionary |
| Known For: | Introduction of the telescope in China |
Manuel Dias the Younger (1574– 4 March 1659)[1] was a Portuguese Jesuit missionary.
Manuel Dias the Younger (Latin: Junior) acquired his epithet to distinguish him from Manuel Dias the Elder (–1639). He is also known as Emanuel or Emmanuel Diaz. His name was sinified as Yang Manuo (Chinese: {{linktext|陽|瑪|諾), and he was also referred to by his courtesy name Yanxi (演西).
Dias arrived in China in 1610, reaching Beijing in 1613. He introduced the telescope into China just a few years after it had been developed in the Netherlands (1608). The telescope was first mentioned in his Tian Wen Lüe (Explicatio Sphaerae Coelestis in Latin or Summary of Astronomy in English) in 1615.[2] In the Tian Wen Lüe he presented the latest European astronomical knowledge in the form of questions and answers. The book was studied and published until the 19th century.