| Sergey Katanandov | |
| Nationality: | Karelian |
| Office: | Russian Federation Senator from the Republic of Karelia |
| Term Start: | 22 September 2010 |
| Term End: | 25 September 2017 |
| Predecessor: | Devletkhan Alikhanov |
| Successor: | Alexander Rakitin |
| Order1: | Head of the Republic of Karelia |
| President1: | Vladimir Putin Dmitry Medvedev |
| Term Start1: | May 12, 2002 |
| Term End1: | June 30, 2010 |
| Predecessor1: | Position established |
| Successor1: | Andrey Nelidov |
| Office2: | Chairman of the Government of Karelia |
| Term Start2: | June 1, 1998 |
| Term End2: | May 12, 2002 |
| Predecessor2: | Viktor Stepanov |
| Successor2: | himself as Head; Pavel Chernov as Prime Minister |
| Birth Date: | April 21, 1955 |
| Birth Place: | Petrozavodsk, Karelo-Finnish SSR, Soviet Union |
| Profession: | Civil Engineer |
| Party: | United Russia |
| Native Name Lang: | ru |
Sergey Leonidovich Katanandov (ru|Сергей Леонидович Катанандов; 21 April 1955) is a Russian politician who served as the leader of the Republic of Karelia, an autonomous entity of Russia, in 1998–2010, first as Prime Minister, then as Head of the Republic.
Katanandov was born in 1955, in the Karelian capital of Petrozavodsk. Educated in civil engineering and law, Katanandov served as Mayor of Petrozavodsk from 1990 to 1998, and became Chairman of the Government of Karelia in 1998. From May 2002 till June 30, 2010, he was the Head of the Republic of Karelia.
Katanandov was born to Karelian parents in Petrozavodsk on April 21, 1955. He graduated from the Faculty of industrial and civil construction of Petrozavodsk State University in 1977. After graduation he worked as a foreman at a construction site. This was followed by a foreman, chief of section, chief engineer of SMU-1 Trust "Petrozavodskstroy, chief engineer of the trust, the head of design and construction of large housing associations. Eventually he ended up becoming a popular politician in Russia. In April 2000, was awarded the Order of Honor. Katanandov is married, and has two sons.