Murdoch and Smith, 66, met in September at his vineyard Moraga in Bel Air, California, and he called her two weeks later, Murdoch told News Corp-owned New York Post, which broke the news of the engagement.
Smith is a widow whose late husband was Chester Smith, a country singer, radio and TV executive.
On March 17 in New York, Murdoch presented Smith with an Asscher-cut diamond solitaire ring, according to the Post.
“I was very nervous. I dreaded falling in love but I knew this would be my last. It better be. I’m happy,” Murdoch told the Post at the time.