Papalii, who made his debut for the Blues mid-way through last season, has become an integral part of the team. The loose forward is a two-time Development Player of the Year and was Rookie of the Year and Club Person of the Year in his debut season.
He was the only uncapped player named in the All Blacks squad on last year's Northern Tour and went on to play two matches, starting in the All Blacks 69-31 win over Japan and then came off the bench against Italy in Rome.
"Dalton is a product of our system, part of our development programme and we earmarked him as a future Blues player from a young age," said Blues general manager performance, Tony Hanks.
"He has played (and captained) our Under-18s and Under-20s, successfully transitioned to the Blues and earned selection to the All Blacks following an outstanding Mitre 10 Cup for Auckland.
"He is not only an outstanding prospect on the field, he is a natural leader off it. He is already developing into a superb professional and we are thrilled he will be with us for a further three years."
Tuipulotu, 26, has already played 21 times for the All Blacks since 2014 and more than 50 games for the Blues. This year he moved into the co-captaincy with Blake Gibson at the Blues, where he is developing as a real leader in the club.
"Patrick is clearly an immense figure in the game and possesses tremendous speed and skill for such a big man. We think New Zealand is still to see the best of him," said Hanks.