Warren Gatland will coach the Barbarians against Wales in their first match under his replacement as coach Wayne Pivac.
Gatland will leave the Wales job after the World Cup in Japan, but will quickly return there with the Baa-baas for the fixture at the Principality Stadium on Nov. 30.
The New Zealander has been in charge of Wales since 2007, winning four Six Nations titles including a superb Grand Slam this year.
"It goes without saying that this match has huge significance to me," Gatland said. "Wales has been my home for the last 12 years and I have thoroughly enjoyed my time here. We have had some great success and we are currently in a hugely important year, culminating at the Rugby World Cup.
"It will be an honour to coach the Barbarians, they symbolise the very best of rugby tradition and are an important part of the international game and I'm hugely looking forward to being part of the Baa-baas club.
"To have the opportunity to return to Cardiff is fantastic and I'm really looking forward to coaching the Barbarians in what I believe is the best rugby stadium in the world and against the best fans in the world."
Pivac, who will take over from Gatland after five years with Welsh Pro14 side Scarlets, said he would use the match as an opportunity to assess players before the 2020 Six Nations.
The match will mark a first meeting between the sides since 2012 and will be part of a double header which includes a first ever match between the Wales and Barbarians women's sides.