Lorde, whose real name is Ella Yelich-O'Connor broke the news on Twitter.
"BEST DAY - went to niagara falls - my dad proposed to my mum after almost 30 years together," wrote the 17-year-old singer.
O'Connor, an engineer, and Yelich, a poet, have three other children together -- Jerry, India and Angelo.
Lorde, whose hit song "Royals" includes the lyric "I've never seen a diamond in the flesh," acknowledged fan jokes.
"Inevitable response yes I know I have seen a diamond now," she added.