"There is a strong ambition at the Region which matches my own, that is, to re-establish the Ospreys at the top level, initially in the Guinness PRO14 and then Europe," Clarke said in a statement on Ospreys' website http://www.ospreysrugby.com.
"I'm highly motivated by the challenge and look forward to working with the coaching and management team... to realise our ambitions playing a brand of rugby that enthuses players and supporters alike."
Former hooker Clarke won eight caps for Ireland and was part of the Ulster team that won the European Champions Cup in 1999.
The Ospreys, who play their final league fixture against the Cardiff Blues on Saturday, are vying to qualify for next season's Champions Cup via a play-off next month.
(Reporting by Aditi Prakash in Bengaluru; editing by Sudipto Ganguly)
