The 33-year-old is the leading appearance holder for the Ospreys with 238 matches and has 125 caps for his country.
"After serious consideration and taking stock of all options, it is
the right decision for my career at this point in time, along with my
personal ambitions on and off the field, my welfare and needs of my
family," Wyn Jones said in an online announcement.
Wyn Jones is preparing to head to Switzerland as Wales ramp up their
training programme for the World Cup and having his future sorted ahead
of the showpiece in Japan is a huge boost for the WRU.
"Alun Wyn is hugely respected across the game and I'm delighted he
has committed his future here in Wales and that he will be continuing to
play for his hometown region," said Martyn Phillips, Group Chief Executive
of the WRU.