Warren Gatland will coach against Wales in the country's first match under Wayne Pivac, after agreeing to lead the Barbarians in Cardiff.
Gatland, who leaves his post after the World Cup in Japan, has been appointed Baa-baas coach for the fixture against Wales at the Principality Stadium on November 30.
"It goes without saying that this match has huge significance to me," said Gatland, who is next week set to be unveiled as Lions boss for the 2021 tour to South Africa.
"Wales has been my home for the last 12 years and I have thoroughly enjoyed my time here.
"We have had some great success with Wales and we are currently in a hugely important year, culminating at the World Cup.
"To have the opportunity to return to Cardiff after the World Cup is fantastic.
"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."
Completing the double header on November 30 will be a first meeting between women's teams representing Wales and the Barbarians.