Justin Trudeau, the son of late Prime Minister Pierre Trudeau, became Canada’s new Prime Minister after his Liberal Party won a majority of Parliament’s 338 seats. Mr. Trudeau, tall and trim at 43, channels the star power if not quite the political heft of his father, who swept to power in 1968 on a wave of support dubbed “Trudeaumania.”

Pierre Trudeau, who was Prime Minister until 1984 with a short interruption, remains one of the few Canadian politicians known in America, his charisma often drawing comparisons to John F. Kennedy. A bachelor when he became Prime Minister, he dated actresses Barbra Streisand and Kim Cattrall.

Justin Trudeau, a former school teacher and member of Parliament since 2008, becomes the second youngest prime minister in Canadian history.

Mr. Trudeau, who has re-energised the Liberal Party since its devastating electoral losses four years ago, promises to raise taxes on the rich and run deficits for three years to boost government spending. His late father, who took office in 1968 and led Canada for most of the next 16 years, is a storied name in Canadian history, responsible for the country’s version of the bill of rights.