Daniel Aloysius Whelton (January 21, 1872 – November 27, 1953) was an American politician who served as the acting mayor of Boston.

[1] When he was five years old, Whelton's father died and he was raised by his mother, who worked as a pastry cook for the admiral commanding the Charlestown Navy Yard.

[3] Whelton became a member of Lomasney's Hendricks Club in the West End, where he began his political career by registering new voters.

Following the death of Collins, Whelton, aged 33, was formally sworn in as acting mayor of Boston, a position he held from September 15, 1905 to January 1, 1906.

[5][6] Whelton was the first native-born Irish-Catholic mayor of Boston and remains the youngest person to hold that political office.