In 1996 he became Minister for Transport and Regional Development when the Coalition government under John Howard took office after the 1996 federal election.
In the first ten days of office Sharp re-opened the East West Runway at Sydney's Kingsford Smith Airport (KSA), which had been closed by the previous Keating Government.
He then reformed the flight paths for KSA under a noise-sharing policy that resolved the issue of aircraft noise complaints that had led to the creation of the No Aircraft Noise Party, who had run candidates in Sydney electorates in the 1996 Federal election.
During 1996 and 1997, in conjunction with Peter Reith, Minister for Industrial Relations, he was tasked to develop a plan to reform Australia's waterfront.
Sharp was Chairman of Parsons Brinkerhoff Advisory Board for a period of six years, retiring in 2010.
From 2004 to 2015 he was Chairman of Power and Data Corporation.In 2018 Sharp became a director of Luerssen Australia and the Australian Maritime Shipbuilding Export Group.
In 2009 at the Federal Nationals Annual Conference he was presented with the Earle Page Award, the Party's highest honour.
Also in 2022 Sharp was appointed as a director of the Bundanon Trust, which is the legacy of Arthur Boyd, one of Australia's greatest artists.
In 2014 it was revealed in the ABC programme A Country Road: The Nationals that sometime before the 1998 Federal election, Sharp had met with then National Party leader Tim Fischer and his deputy John Anderson for a luncheon and they were surprised to learn from each other that they all intended to retire at the forthcoming election.
They did not think it was a good idea for all of them to retire at the same time as it did not give a positive image to the party, which is battling against perceptions that it does not have a certain future.