Seria is a town in the Belait District of Brunei Darussalam. Its full name is Pekan Seria (Pekan is the Malay word for "Town").
Seria was originally known as Padang Berawa which is Wild Pigeon's Field in Malay.
According to some facts, the name 'Seria' came from the name given by the British authorities at that time, which known as the South East Reserved Industrial Area. The Industrial Area is located near the place where oil was first discovered in the area in 1929.
The first commercial oil well was spudded in 1929 in Padang Berawa on the west bank of the Seria river (Sungai Seria).
Seria area was gazetted as municipal area in 1936. The town came under the authority of the Kuala Belait Sanitary Board which also had responsibility for the municipal area of Kuala Belait.
The first landing of the Japanese invasion force during World War II in Borneo was at Seria where the Left Flank of the Kawaguchi Detachment came ashore about 04:40 on 16 December 1941, nine days after Pearl Harbor. They were faced with a scene of devastation of the oilfields due to "Operation Denial" carried out by employees of the British Malayan Petroleum Company (now Brunei Shell Petroleum) and the 2nd Battalion, 15th Punjab Regiment, and British Army Royal Engineers. The invasion force continued oil drilling units and restoration of the oilfields began immediately under Sato, Chief Engineer. Over the next three years, the Japanese restored production to nearly pre-war levels, the activity being hectic as other sources of supply to the Japanese war machine were closed off, so much so that most of the oil fueling the Japanese in the last six months of the war came from Seria. Operation "Ha-Go 2", the Japanese denial exercise commenced on 10 June 1945, the day of the Australian liberation forces landing at Muara. The fires could be seen 100 km out to sea. When the Australian 9th Division as part of Operation Oboe Six eventually entered Seria on 29 June 1945, the situation was chaotic, with 38 oil well fires, demolished buildings and wrecked installations. By 17 August 1945, when American fire fighting teams (Patton and son) arrived, 26 of the fires had been put out by oilfield staff assisted by a detachment of the Australian Royal Engineers. By November, production was restored, albeit stored in temporary tanks, and oil export to Lutong recommenced on 11 December 1945.