Duncan Smith (born 17 May 1983) is an Irish Labour Party politician who has been a Teachta Dála (TD) for the Dublin Fingal East constituency since the 2024 general election, and previously for the Dublin Fingal constituency from 2020 to 2024.

[5][6] After his election to the Dáil, James Humphreys was co-opted to Smith's seat on Fingal County Council.

[7] He was one of two TDs to nominate Alan Kelly for the position of Labour Party leader in the 2020 leadership election.

[8] In 2021, Smith received media attention for criticising Michael and Danny Healy-Rae in the Dáil, after the two TDs had accused Labour of being "anti-worker" after proposing a zero-COVID strategy, accusing the Healy-Raes of coming from a background of "Fianna Fáil privilege and millions and millions of euros" and "pretending to be working class.

[13] Smith was the Labour Party Director of Elections for Ivana Bacik in the 2021 Dublin Bay South by-election.