The national telecommunications operator has appointed Kalugin, a personal friend of three-term Russian president Vladimir Putin, after former president Alexander Provotorov stepped down.
Sergey Kalugin said: "It is with a sense of great honour and responsibility that I take up this post as president of one of the largest telecommunications companies in Russia.
“Through our dedication and efficiency, I am certain that Rostelecom faces a great future.”
Kalugin, 46, has a wealth of experience within telecommunications after serving as CEO of OJSC National Telecommunications from 2007 to 2008 and from 2009 to 2012. The 46-year-old has also been managing partner at WebMediaGroup since 2009.
It was rumoured that Mr Kalugin was a personal recommendation from president Putin.