28 April – The Bersih 3.0 rally take place in Kuala Lumpur. More than 250,000 people take part in the rally. Police fired teargas and water cannon to the protestors near Dataran Merdeka and arrest more than 500 people in the demonstration.[14]
7 June – Wedding Ceremony of Nurul Wahab married Eric Daniel Deep as honeymoon to briding ceremony with theme "Aura Paris" source of Harian MetroKuala Lumpur Edition on next day.
26 July – One crew members was killed and three others were injured in an MV Bunga Alpinia 3 tanker explosion in Labuan.[25]
August
27 July - 12 August – Malaysiacompeted at the 2012 Summer Olympics in London, United Kingdom. On August 5, Malaysian badminton player, Lee Chong Wei, won a silver medal for the second time.[26] On August 9, Malaysian diver Pandelela Rinong won a bronze medal in the 10 metre diving platform for the first time.[27] This was the first female Malaysian athlete to win a medal at the Olympics, as well as the first to win an Olympic medal in any sport other than Badminton.[28]
31 August – The Himpunan Janji Ditepati gathering was held at Stadium Nasional, Bukit Jalil, Kuala Lumpur. It would set a world record of having one million tweets hashtaged #Merdeka55 containing messages of independence between 8:15 and 9:15pm.[30]
September
4 September – Two Malaysian medical students were killed in the road crash at Vladimir, Russia.[31]
11 September – The preliminary report of Malaysia Education Blueprint 2013-2025 was introduced. The government made the report based on public opinions about education in Malaysia. There are 11 areas of reform which will be made in 3 phases.[32]
13–15 September – The Duke and Duchess of Cambridge (William and Kate) were on a 3-day official visit to Malaysia, representing Elizabeth II for the Royal Jubilee celebrations.[33]
16 September – The Malaysia Day celebrations was held at Lapangan Terbang Lama, Bintulu, Sarawak. This is the first such celebration held on a large scale in Sarawak.[35]
18 September – Mechanical heart girl, Tee Hui Yi, who went underwent a successful double heart transplant on 5 October 2007, died at the Batu Pahat Hospital at 10:02am after complaining of back and chest pains at about 7am.[36]
22 September – Muslims and non-Muslims in various parts of Malaysia made peaceful protests over the film Innocence of Muslims.[37][38]
22 September – The Automated Enforcement System (AES) came into force at all major roads, highways and expressways nationwide.[39]
10 October – Six of family killed while two others were seriously injured when they car collided with an express bus at Kuantan-Kuala Terengganu road near Meraga Beris, Kijal, Terengganu.[41]
25 October – The Kota Kinabalu International Airport (KKIA) was closed Thursday night after the runway lights malfunctioned, forcing several incoming and outgoing flights to be cancelled or rescheduled and leaving many passengers stranded.[44][45]
27–31 December – The Karnival Sayangi Selangor Yakini BN is held at I-City, Shah Alam, Selangor. Other carnival also begin in Dataran Kemerdekaan Shah Alam (Shah Alam Independent Square).[57]
National Day theme: 1Malaysia; 55 Tahun Merdeka Janji Ditepati (1Malaysia; 55 Years of Independence Promises Fulfilled)
Malaysia Day theme: Janji Ditepati Rakyat Sejahtera
Malaysia was only formed on September 16, 1963. Prior to that date, Peninsular Malaysia was known as Malaya, Sarawak under Crown Colony of Sarawak and Kingdom of Sarawak and Sabah under North Borneo.