Headteacher Peter Harrison will accompany pupils to the specifically priced family-friendly fixture - which has child tickets available at £10 - for the sixth consecutive year this weekend and is extremely proud to support Dan at the home of Welsh rugby.
"Tomorrow will be a great occasion for the school and we are immensely proud to support Daniel who is not only a wonderful role model for the children on the rugby field, but he is also a fantastic level-headed and intelligent individual," he said.
"Last year we supported Daniel as he made his first international start from the bench against Canada and after this great occasion we were thrilled to welcome him back to school for a certificate presentation with year 7."
"All the children are behind Daniel and we wish him all the success on the field this weekend. I'm sure that all 747 of the group will be shouting his name."
Biggar retained his place in the Wales squad following the two-Test summer tour of the USA and Canada and is looking forward to starting against the Samoans at the Millennium Stadium with the support of his former school.
He said: "It's great that the school are coming to support what will be a very big day for me. I hope that the group have a fantastic evening at the Millennium Stadium. I'll certainly be looking out for them in the crowd and I'll try and give them a wave if I can."
Teachers and pupils at the school have some great memories of the Millennium Stadium having celebrated a Gowerton Comprehensive U14 win at the Coca-Cola Schools Cup Finals day in 2008.
Former Wales internationals scrum-half Andy Williams and full-back David Weatherley also attended the school as well as Llanelli hooker Craig Hawkins.
The Welsh Rugby Union are advising fans to arrive early to avoid expected queues with a bumper walk up crowd likely.
Tickets are on sale priced at £10 for under 16s and £15 for adults from Ticketline on Westgate Street and from the Cardiff Arms Store at the bottom of Gate 3.
Pre-ordered ticket collections will begin at 8am from the Cardiff Arms Store on Friday.