Byrne studied at Memorial University of Newfoundland where towards a joint Bachelor of Arts / Bachelor of Education program majoring conjointly in Newfoundland Studies and Religious Studies. In 1984, he was elected President of the University’s Council of the Students’ Union.
He began his career as an adult educator specializing in curriculum development and serving as a skills training coordinator, and he went on to serve as Administrator of the Atlantic Labour Training Trust Fund. For five years, as well, he served as a management consultant.
Byrne was elected to represent the district of Kilbride in the provincial elections of 1993, 1996, 1999 and 2003. As a Progressive Conservative Member of the House of Assembly, he served in several shadow portfolios including Post-secondary Education, Employment and Labour Relations, Environment, and Industry, Trade and Technology; and as Chair of the Public Accounts Committee.
He served as Leader of the Progressive Conservative Party and Leader of the Opposition from 1998 to 2001. He stepped aside in 2001 to allow successfully St. John's businessman Danny Williams to assume the leadership. Williams and the Progressive Conservatives then went on to win the 2003 provincial election.
Byrne was appointed as the Minister of the Departments of Mines and Energy and Forest Resources and Agrifoods (now known collectively as the Department of Natural Resources) and Government House Leader on November 6, 2003 by Premier Williams, positions he held until June 21, 2006.
On June 21, 2006, Premier Danny Williams announced that he had he requested the Byrne's resignation as a result of an audit of the financial records of the House of Assembly by the Auditor General of the province. The resignation was requested after the Auditor General expressed concern to the Speaker of the House of Assembly over financial issues. Byrne complied with the request to step aside effective immediately.
On June 22, 2006, the provincial Auditor General released a report on Byrne's constituency allowance claims in the 2003 and 2004 fiscal years. While Byrne had been eligible for a maximum claim of $31,500 for that period, the Auditor General had found evidence that he had claimed a total of $326,642 in excess of that amount. The Auditor General recommended that the case be turned over to the Department of Justice for review.
The Auditor General also reported, on June 22, that three other members of the House of Assembly were being investigated for similar actions, one former Liberal member, one sitting Liberal member, and one sitting New Democratic Party member.
On June 23, the Royal Newfoundland Constabulary began a criminal investigation based on the findings of the Auditor General.
Ed Byrne announced on November 28th that he was resigning from provincial politics effective January 1 2007.