The English version of Arabic-language channel Al Jazeera beat competition from Sky News and BBC News after the judges praised its coverage of the Arab Spring last year.
The judging panel said that the revolutions that spread across the Middle East in 2011 proved a "breakthrough moment" for Al Jazeera English, as the channel became "essential viewing for insight and understanding of the evolving story".
During a ceremony filled with tributes to Sunday Times war reporter Marie Colvin, who was killed in Syria on Wednesday morning, Al Jazeera also took home the 'Innovative News' prize' for its Skype and social media-based show The Stream: Bahrain.
Alex Crawford was named 'Television Journalist of the Year' for the third year in a row. She was praised for reporting from the front line of the war in Libya, in particular for capturing the first proof that Muammar Gaddafi was attacking his own people.
Sky News took home four prizes in total, including the 'News Coverage - International' accolade for its overall coverage of the Libyan revolution, which the judges praised as showing "extraordinary bravery, endurance and outstanding judgment, not to mention some brilliant achievements in just getting to the right places at the crucial moment".
The satellite broadcaster was also awarded the 'News Coverage - Home' prize for its reporting of the rioting and unrest that engulfed the UK last August. Sky News' Anna Botting was named 'Presenter of the Year', beating Channel 4's Jon Snow and ITV News' Mark Austin, who hosted the ceremony.
'Scoop of the Year' went to Panorama: Undercover Care, the moving BBC One documentary that exposed abuse at a care home, leading to the facility being closed down.
"In a year when television again produced investigative journalism which is truly in the public interest, the 'Scoop of the Year' revealed uncomfortable truths and helped to change things for the better," said the judges.
The programme also took home the 'Current Affairs - Home' prize, while Channel 4's Sri Lanka's Killing Fields - featuring shocking footage of abuses during the country's civil war - was handed the 'Current Affairs - International' award.
'News Programme of the Year' went to BBC Two's Newsnight and 'Specialist Journalist of the Year' went to its reporter Paul Mason, particularly for his analysis of the economic crisis in the Eurozone.
'Young Journalist of the Year' was handed to the BBC's Joe Casey, while Japan's NHK received the 'Judges' Award' for its coverage of the Japanese earthquake and tsunami last year.