| Siavash Mirshams Shahshahani | |
| Birth Name: | Siavash Mirshams Shahshahani |
| Birth Date: | 1942 5, df=yes |
| Birth Place: | Iran |
| Nationality: | Iranian |
| Thesis Title: | Global Theory of Second Order Ordinary Differential Equations on Manifolds |
| Thesis Year: | 1969 |
| Thesis Url: | https://math.berkeley.edu/people/grad/siavash-mirshams-shahshahani |
| Awards: | Lasting Figures (2003) |
Siavash Mirshams Shahshahani (Persian: سیاوش میرشمس شهشهانی) (born 1942) is an Iranian mathematician. He is a professor of mathematics and head of Mathematical Sciences Department at Sharif University of Technology. He headed up the IRNIC registry for the .ir ccTLD until his retirement from that position in late 2008. He has also served as a director of APTLD (the Asia Pacific Top Level Domain Association) between 2007 and his retirement from that position in February 2009.
Shahshahani completed his PhD under the supervision of Stephen Smale at the University of California at Berkeley in 1969. He has since devoted a substantial part of his career to mathematical education.