Russia–Sri Lanka relations
The Soviet Union established diplomatic relations with Sri Lanka on December 3–6, 1956. In 1958, the USSR and Sri Lanka signed an agreement on economic and technical cooperation. In 1967, they built a steel mill (production capacity - 50,000 tons of stock per year), a tire plant, and a construction materials plant near Colombo all with the assistance of the Soviet Union.
Russian Federation relations
In UN, Russia has always supported Sri Lanka in almost every resolution brought forward. The most notable one is during the final stages of the Sri Lanka's civil war in 2009, European Union members along with North Americans (Canada, Mexico) brought a ceasefire bill against Sri Lanka Army. But China and Russia overwhelmingly vetoed against the bill and struck down. Later the war crime bill table by the West against Government of Sri Lanka, also stuck down by Russia, China, African Union and several other countries.
Sri Lanka also reacted in favor of Russia during the Ukrainian crisis,and acknowledged the concerns of Russia as justifiable. 
Russia helped Sri Lanka to obtain Russian based weapons from several countries throughout the past 30 years. Examples of this would be Mikoyan-Gurevich MiG-27 used by Sri Lanka Air Force and T-54/55 battle tanks used by Sri Lanka Army.
Sri Lanka and Russia have recently ramped up cooperation on expanding the tea trade between the two nations. Currently, approximately 17 percent of Sri Lanka's tea exports go to Russia. Sri Lankan teas account for 30% of Russia's tea market
- Russia pledges support to Lanka in its crackdown on LTTE Zee News - May 07, 2009
- “While acknowledging the justifiable concerns of the Russian Federation, Sri Lanka also welcomes attempts at de-escalating the tension. Sri Lanka is confident that the parties concerned would be able to resolve the issues arising out of the recent developments, through a legitimate democratic process, enabling harmonious co-existence of the people of Ukraine.” - See more at: http://www.nation.lk/edition/breaking-news/item/26839-ukraine-crisis-lanka-regrets-presidents-unconstitutional-removal.html#sthash.888W7iUA.dpuf%7C“While acknowledging the justifiable concerns of the Russian Federation, Sri Lanka also welcomes attempts at de-escalating the tension. Sri Lanka is confident that the parties concerned would be able to resolve the issues arising out of the recent developments, through a legitimate democratic process, enabling harmonious co-existence of the people of Ukraine.” - See more at: http://www.nation.lk/edition/breaking-news/item/26839-ukraine-crisis-lanka-regrets-presidents-unconstitutional-removal.html#sthash.888W7iUA.dpuf
- Sri Lanka targets Russia with specialty teas Lanka Business Online - December 19, 2011
- (English) Sri Lanka Renews 51 Year Old Diplomatic Relationship with Russia
- (Russian) Documents on the Russia – Sri Lanka relationship at the Russian Ministry of Foreign Affairs
- Sri Lanka president met his Russian counterpart Dimitry Medvedev and Chinese President Hu Jintao
- Sri Lanka – A Rajapaksa Factor
- Sri Lanka President warmly welcomed in Russia
- Rajapaksa visits Russia to bolster ties
- Russian envoy calls for stronger SL-Russia ties