Although information regarding Hryshchenko's appointment has been circulating in the media since the beginning of June, an official decree was only posted on the president's website on Tuesday.
Hryshchenko, 55, also a former Ukrainian ambassador to the U.S., served as the ex-Soviet state's top diplomat from September 2003 to February 2005 in the pro-Russian government of Viktor Yanukovych.
The appointment of Hryshchenko raised hopes that relations between the two former Soviet republics, soured over Kiev's bid to join NATO, would improve.
In April this year, Hryshchenko was appointed first deputy head of Ukraine's National Security and Defense Council. He will retain the post.
The former ambassador to Russia, Oleh Dyomin, retired from his post on April 4 at the age of 60.
