Beazley became a protege of Bob Hawke, Labor leader from 1983, and in that year he was appointed Minister for Aviation in Hawke's first ministry. He was Minister for Defence, with a seat in Cabinet, 1984-90. He was then Minister for Transport and Communications (1990-91), for Finance (1991), for Employment, Education and Training (1991-93) and Finance again (1993-96). He supported Hawke in his leadership battles with Paul Keating in 1990-91, but retained his position when Keating deposed Hawke and became Prime Minister in December 1991. Beazley was Deputy Prime Minister 1993-96. At the 1996 elections Beazley shifted to the safer seat of Brand, south of Perth.
In 1996, on the defeat of the Keating government by John Howard, Beazley was elected unopposed as Labor leader and became Opposition Leader. He campaigned against Howard's Goods and Services Tax (GST) and came very close to winning the October 1998 federal election: Labor polled a majority of the two-party vote but failed to win enough seats.
In mid 2001 Labor was well ahead in the opinion polls and seemed set to win the elections due at the end of the year, but in August a political crisis erupted when the Howard government refused to allow the Tampa, a Norwegian freighter full of (alleged) Afghani and Iraqi asylum seekers, to land in Australia. Howard was able to campaign effectively on the issues of border protection and national security, a task made easier for him by the September 11 terrorist attacks. When the November 2001 election was announced, Howard had taken a commanding lead in the polls and seemed set for a huge victory. But Beazley's dogged campaigning regained some of this ground and Labor suffered a net loss of only four seats.
Beazley resigned the Labor leadership after the elections and was succeeded by Simon Crean. But by 2003 Crean had failed to make any headway against Howard and Labor MPs began to fear that Howard would easily win the elections due in 2004. Crean's opponents persuaded Beazley to attempt a return to the leadership by challenging Crean. The Labor Caucus (parliamentary Labor Party) re-elected Crean in June 2003, not convinced that Beazley offered a better alternative. Some Beazley supporters continued to plot against Crean, however, and Beazley refused to rule out a further challenge.
On 27 November Crean's closest supporters told him that he had lost their confidence, and the next day Crean announced his resignation. Beazley immediately announced that he would be contesting the leadership when the Labor Caucus met on 2 December. His only opponent was the party's economic spokesperson, Mark Latham.
On 2 December Latham defeated Beazley by 47 votes to 45, ending what was almost certainly Beazley's last chance to lead the Labor Party. After the ballot Beazley announced that he would remain in politics as a backbench member and would recontest his seat at the 2004 elections.
On the 14th of July however, after a spray of criticism from the US on its Iraq policy, Latham suprised the electorate by announcing with Beazley that he would be returning to the Labour front bench as Opposition Defence Spokesman. It is to be seen how the electorate responds to this in the months leading up to the 2004 election.