The estate produces Cabernet Sauvignon, Merlot, Cabernet Franc, Petit Verdot and Sauvignon Blanc.
Murdoch, whose media empire includes The Sun, The Times, Twentieth Century Fox and HarperCollins, read about Moraga Vineyards and winery in one of his newspapers, The Wall Street Journal.
He bought the estate from Thomas Jones, former chief executive of security firm Northrop, for an undisclosed fee. The property, which comes with a house, was listed at £19.25 million.
Jones and his wife Ruth took it on in 1959 after buying it from Victor Fleming, director of Gone with the Wind and The Wizard of Oz.
His representatives have declined to comment on the purchase, but Murdoch tweeted: “About to celebrate buying beautiful small vineyard right in LA. Great wine, Moraga, owned by great Angelino, Tom Jones. Time cover,1961!”
Jim Kline, the estate agent who handled the sale, said: “I think he’s very interested in learning the wine business and carrying on Moraga the way that it has been. I think it’s something that intrigues him. And it’s a spectacular property.”