The 17 year-old singer-songwriter's father Vic O'Connor, a civil engineer, proposed to her poet mother Sonja Yelich at the Niagara Falls, reported Us magazine.
Lorde shared the exciting news with her fans on Twitter.
"Best Day... Went to Niagara Falls - my dad proposed to my mum after almost 30 years together," Lorde posted.
In another post, the young songstress also tweeted, "Inevitable response, yes I know I have seen a diamond now," referring to the lyrics at the start of the 'Royals.