| Ion Tănăsescu | |
| Birth Date: | 23 February 1892 |
| Birth Place: | Bucharest, Romania |
| Nationality: | Romanian |
| Death Place: | Bucharest, Romania |
| Known For: | Lehmstedt-Tanasescu reaction |
Ion Tănăsescu (February 23, 1892 - December 28, 1959) was a Romanian chemist.
He discovered the Lehmstedt-Tanasescu reaction, which was improved by Kurt Lehmstedt. He studied at the University of Bucharest and the University of Cluj. He was elected a titular member of the Romanian Academy in 1955.