Under the deal, Google will be the exclusive internet search and keyword advertising partner for the Fox network and its growing number of web properties. Fox will receive $900m from Google by 2010 in revenue share payments.
Google will also have a right of first refusal on display advertising sold through third parties on Fox Media's network.
MySpace, bought by Fox's News Corp last year for around $580m, is attracting more than 250,000 new users a day, and is expected to reach a total of 100m worldwide this week.
The deal comes as rival US media group Viacom is considering a bid for MySpace's rival site Bebo after its failure to beat News Corp in the race to buy MySpace last year.
Peter Chernin, president and chief operating officer of News Corporation, who negotiated the deal, said: "Our partnership with Google underscores News Corp's continued evolution to become a powerful force in the digital media marketplace."
Chernin also indicated that this could be the start of further partnerships with Google across the group.
He said: "This is an exciting time in our history as a forward-thinking media company and this is just the first of many steps we plan to take with Google. We look forward to expanding our relationship into many new areas over years to come."
Eric Schmidt, chief executive officer of Google, said: "MySpace.com is a widely acknowledged leader in user-generated content, and incorporating search and advertising furthers our mission of making the world's information universally accessible and useful."
As well as MySpace, which was set up in 2003, other Fox-owned sites to benefit from the deal include movie database Rottentomatoes.com, lifestyle site for men askmen.com, and gaming sites Gamespy.com and Gamespyarcade.com.
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