European President Jean-Claude Juncker has expressed his "horror and sadness" upon learning of the blasts. He said the European Union stood "ready to support" Sri Lanka.
UK Prime Minister Theresa May also condemned the Sri Lanka bombings.
"The acts of violence against churches and hotels in Sri Lanka are truly appalling, and my deepest sympathies go out to all of those affected at this tragic time.
"We must stand together to make sure that no one should ever have to practise their faith in fear," May said on Twitter.
Meanwhile, the governments of the United Arab Emirates and Bahrain denounced the bombings as "terrorist attacks."
"The UAE affirmed its firm stance against all forms of violence, terrorism and extremism, targeting all without distinction between religion and race," the UAE Ministry of Foreign Affairs and International Cooperation said.
Both countries expressed solidarity with the government of Sri Lanka.