The 29-year-old made 48 appearances in total for New Zealand, scoring five tries since his debut against Argentina in 2001.
The blindside flanker cum No8 has joined the Welsh region from French outfit Toulon and will remain at the Liberty Stadium until the end of the 2010/11 season.
"As an organisation, we have always looked to bring in people of real quality from outside the region when we feel that they have the right characteristics to complement what we already have here, and Jerry Collins certainly fits that description," said Andrew Hore, Ospreys elite performance director.
"He is a proven world-class performer, who brings with him both a real hard edge and 'go-forward'
ability, as well as an uncompromising attitude on and off the field.
"He will complement the other loose forwards that we have at the Ospreys, and importantly, will be available for selection throughout the season, providing valuable cover for the times when we lose so many players to the Welsh side.
"The Ospreys remain 100 per cent committed to producing home grown talent, and are immensely proud of our record in bringing through players for both the Ospreys and Wales teams.
"As we have shown before, there are occasions where we need to go outside of the region to identify and recruit true leaders in their field, who can help to develop and nurture our own young talent. In Jerry Collins we have certainly got a true leader."