May 31, 2009 (Sunday)
- The People's Justice Party wins the by-election in Penanti, Penang, Malaysia. (Bernama)
- Russian cyclist Denis Menchov wins the 2009 Giro d'Italia in Rome, Italy. (New York Times)
- Late-term abortion provider George Tiller is shot and killed in Wichita, Kansas, United States. (The Wichita Eagle)
- South Ossetia holds its parliamentary election. (Al Jazeera)
- Six people are killed during battle between Hamas militants and the Palestinian National Authority's Preventive Security Service in the West Bank. (BBC)
- Two men are charged with plotting to assassinate former Hong Kong Democratic Party Chairman Martin Lee. (AFP via News Limited)
- At least 44 inmates escape from a prison in Bagua Grande, Peru. (BBC)
- A man steals €6 million in jewellery from Chopard in Paris, France. (BBC)
- Thousands of demonstrators gather in Hong Kong to commemorate the upcoming anniversary of the Tiananmen Square massacre of June 4, 1989. (Straits Times) (BBC)
- At least 72 protesters are arrested after battling with the National Police Agency in Seoul, South Korea. (The Korea Times)
- Robin Söderling of Sweden defeats world-number-one, four-time French Open and defending champion Rafael Nadal of Spain in tennis's 2009 French Open. (Sky News) On the same day, women's defending champion Ana Ivanovic also bows out, losing to Victoria Azarenka. (The Telegraph)