Audrey Eu was born on 11 September 1953 in Hong Kong. She studied at St. Francis' Canossian College from 1960 to 1970 and matriculated from St. Paul's Co-educational College in 1972.
She earned her Bachelor of Laws from the University of Hong Kong and her Master of Laws from the University of London. She was called to the Bar in England in 1977 and the Bar in Hong Kong in 1978 and was appointed as a Queen's Counsel in 1993 (known as Senior Counsel since 1997). She continues to practice and specialises in civil law. Notable pupils of hers include Andrew Cheung, current Chief Judge of the High Court. Before entering politics, Eu was the chairlady of the Hong Kong Bar Association. She shot to prominence on the right of abode issue, at the time of the transfer of sovereignty to the People's Republic of China in 1997, she held a firm stance against the interpretation of the Hong Kong Basic Law by the National People's Congress. In 2011, she was made awarded an honorary fellowship by the London School of Economics and Political Science.
Eu decided to enter into politics in 2000, and was successful in gaining a Legislative Council seat at a byelection replacing Gary Cheng after he gave up his seat due to various negative news. She then became a founding member of the Basic Law Article 23 Concern Group, which later became the Basic Law Article 45 Concern Group, then the Civic Party in 2005.
In 2002, when the Hong Kong Government wanted to alter the existing Article 23 concerning treason and sedition, Eu, with some other notable members of the Bar, including Alan Leong, Margaret Ng, Ronny Tong, formed the Basic Law Article 23 Concern Group. Before the draft Bill became public, Eu put forward strong opinions and statements opposing certain measures of the Article 23 legislation. Her campaigning helped her significantly raise her public profile after 1 July 2003, demonstrations.
Concern started to grow among Hong Kong residents later about Articles 45 and 68 of the Basic Law in 2004. There were also uncertainties concerning the future of the next 2007 Chief Executive election and the next 4th LegCo elections in 2008.
In response, Eu, along with other barristers including Margaret Ng and Ronny Tong, formed the Basic Law Article 45 Concern Group that advocated fully democratic processes in the form of universal suffrage in both elections. She found most support with the middle-class.
Eu ran for the 2004 LegCo election for the Hong Kong Island constituency in the same ballot as Cyd Ho from The Frontier. The "Eu-Ho" pair obtained 73,844 votes which resulted in Eu obtaining a seat at the expense of Ho, who lost out to her nearest DAB rival Choy So Yuk by a mere 815 votes. This was seen as a blunder by the pan-democratic camp, as Hong Kong Democratic Party LegCo candidate Martin Lee had more than enough votes to be elected, directly affecting Cyd Ho's election chances.
Eu was the founding leader of the party, and held the office from 19 March 2006 to 8 January 2011.
She stood for and was returned in the Hong Kong Island geographical constituency for the Hong Kong legislative election, 2008. She was placed second on the Civic Party ticket, behind newcomer Tanya Chan, who was also elected. After deducting the quotient required for the first seat, the remainder to Eu was only 30,362, enable Eu to win a seat in the constituency with the lowest number of vote. She got 525 votes less than her former running mate in the 2004 election Cyd Ho.
However, Eu lost her seat in the Legislative Council in September 2012.
In the debate over the Hong Kong government's 2009 reform package (referred to by government as the '2012 constitutional reform package') she was among the firmer voices in the pan-democratic camp, supporting the January 2010 resignation by five pan-democrat Legislative Councillors to force a by-election in which they re-stood (and were re-elected), intended as referendum on democracy.
Following the vote, she was invited by Chief Executive Donald Tsang to participate in a live televised one-on-one debate with him on the package. The offer surprised many, given her forthright position among democrats. In public opinion polls after the debate on 17 June 2010, she was widely considered to have won (71% to 15%).
In the run-up to 23 June 2010 Legco vote on the reform package she refused support, saying that it did not go far enough towards democratic expectations, even if it included the Democratic Party's compromise proposal to have the five new district council functional constituency seats returned by popular election.
Eu is a patron of St John's Cathedral HIV Education Centre and was formerly a member of the Consumer Council's Management Committee of its Consumer Legal Action Fund.
Her younger brother Benjamin Yu is also a senior counsel and serves as legal counsel for Chief Executive-in-Council.