The talented 24-year-old openside is considered one of the best poachers of the ball in world rugby and retaining his services for next year's British and Irish Lions series and the World Cup is a big boost to the Wallabies.
"David has made an enormous contribution to rugby as a player and an outstanding individual," acting Australia Rugby Union chief executive Matt Carroll said.
"His leadership combined with his form on the field is a huge asset for Australia.
"We are very pleased to be able to have David available for the Wallabies not only for next year's Lions Tour, but the next Rugby Championship series and quite possibly the next Rugby World Cup in London in 2015."
Twice winners Australia were handed a tricky draw for the group stages of the 2015 World Cup alongside hosts England and Wales earlier this month.
But negotiating a passage to the quarter-finals of the showpiece will be much easier with the services of Zimbabwe-born Pocock, who has won 45 caps for Australia, captained the side on numerous occasions and has twice been nominated for the prestigious IRB international player of the year award.
He will play for the ACT Brumbies in the next Super Rugby season after leaving the Perth-based Western Force side earlier this year.
In June, Pocock led the Wallabies to a 3-0 home series win over Wales before injuring his knee against the All Blacks in August and missing most of the European Tour which concluded earlier this month.
His re-signing follows that of controversial fly-half Quade Cooper, who agreed a new two-year deal earlier this month after protracted talks.