Smith was born in Melbourne, to parents Alan Smith, a chemistry teacher, and Noel Smith, a medical secretary. Tony was the youngest child, with two older sisters: Christine and Heather. He was educated first at Kerrimuir Primary School in Box Hill North before attending Carey Baptist Grammar School in Kew. He studied Commerce and Arts at The University of Melbourne. He was president of the Melbourne University Liberal Club, and is now an honorary life member.
On 23 January 2007, Smith was appointed Parliamentary Secretary to the Prime Minister, John Howard. He managed to hold his seat of Casey by a considerable margin at the federal election in November of that year, although the Liberal-National Coalition was defeated. On 22 September 2008, Smith was appointed Shadow Assistant Treasurer by Opposition Leader Malcolm Turnbull. Smith had previously been Shadow Minister for Education, Apprenticeships and Training. He was appointed Shadow Minister for Communications in a reshuffle which took place on 8 December 2009. When Malcolm Turnbull's hold on the Liberal leadership became terminal, it was speculated that Smith was part of a "two-Tony" ticket in which Smith would be the running mate of Tony Abbott in a leadership challenge. Although Abbott successfully challenged Turnbull for the Liberal leadership on 1 December 2009, Smith was not Abbott's running mate, and Julie Bishop remained deputy under Abbott. Despite the speculation that they would make a leadership team in 2009, Abbott and Smith do not seem to be close as Abbott demoted Smith after the 2010 election. When Smith sought the speakership in 2015, it is understood that Abbott as Prime Minister backed rival contender Russell Broadbent as the Government's candidate for Speaker over Smith. In 2015, the Daily Telegraph reported that there was an "internal view" in the Liberal Party that Abbott blamed Smith for the Coalition's narrow loss at the 2010 election due to Smith's perceived mishandling of the Coalition's broadband policy when Shadow Communications Minister. In the new Abbott shadow ministry announced after the August 2010 election, Smith was appointed Shadow Parliamentary Secretary for Tax Reform and Deputy chairman, Coalition Policy Development Committee. He was interviewed extensively in the ABC documentary The Howard Years.
Following the resignation of Bronwyn Bishop as Speaker of the House of Representatives in August 2015 over entitlement rorts dating back a decade, the Liberal Party nominated Smith as the party's candidate to replace Bishop. The House of Representatives elected Smith unopposed. He has pledged to absent himself from the Liberal party room for the duration of his speakership to protect the neutrality of the chair. He also eschewed the traditional full attire of the Speaker, instead continuing to wear an ordinary business suit. Smith was re-elected Speaker unopposed after the 2016 and 2019 federal elections. He is the first Speaker to be elected unopposed on three occasions since Frederick Holder, the inaugural holder of the position.