Zac Guilford (Reuters)
Image credit: Reuters
The 24-year-old Guilford, who can also play at fullback, was part of the 2011 World Cup winning squad, notably scoring four tries against Canada.
Clermont, the 2013 Heineken Cup runners-up, lead the standings in the Top 14, which they won for the first time in 2010 after 10 failed attempts in the final.
Guilford, who has an option for an extra year on his contract, is the latest addition to a series of top-notch recruits for Clermont after France lock Sebastien Vahaamahina and Wales and British & Irish Lions centre Jonathan Davies.
Sir Chris Hoy & Joanna Rowsell