Gibbes was the inspirational Captain of the New Zealand Maori team for their historic win over the British and Irish Lions last summer and also featured for the All Blacks in the Lions series whitewash. Jono is currently captaining the Maori team at this summer's Churchill Cup.
Gibbes currently has a contract with the New Zealand RFU which runs until the end of the 2006 season.
Gibbes will join fellow All Black star Justin Marshall in a much improved Ospreys side next season.
"Gibbes is a top-quality international rugby player and his signing, along with that of Justin Marshall, signals our intent to be a far more competitive team in Heinekenrugby next season," said Ospreys managing director Mike Cuddy on Tuesday.
"Jono is a proven leader of men and will bring a wealth of experience to our squad for what is already an eagerly anticipated season."