Fernando Santos' side triumphed at the 2016 European Championship and Goncalo Guedes' second half strike gave them a narrow victory in Porto which Santos said was evidence of their unity as a team.
"For the last five years, we have been an almost indestructible family who know what we are capable of doing," he said. "We knew we could win this match."
The victory was achieved through Guedes, the Valencia winger smashing in from the edge of the area following Bernardo Silva's clever cutback, though Dutch goalkeeper Jasper Cillessen will be disappointed he did not keep the effort out.
The Dutch looked to get back into the game but Memphis Depay's powerful header was well saved by Wolves number one Rui Patricio and ex-Middlesbrough midfielder Marten de Roon lashed over.
England finished third in the tournament after a victory on penalties over Switzerland in Guimaraes.
The game was billed on the clash of the two influential captains - Portugal forward Cristiano Ronaldo and Netherlands centre-back Virgil van Dijk.
Both players claimed silverware at club level last season, Ronaldo winning the Serie A title with Juventus, while Van Dijk contributed to ending Liverpool's seven year wait for a trophy by triumphing in the Champions League.
Ronaldo, 34, scored a sublime hat-trick in the semi-final victory over Switzerland but was unable to add to his 88 international goals, seeing a thumping, goalbound drive blocked by the towering Van Dijk.
The closest he came to netting was when he skipped past two defenders from the left, but stuck a shot straight at Barcelona's Cillessen. He also smashed a free-kick wide late on.
Former Southampton and Celtic player Van Dijk was his solid, assured self at the back but could do nothing about the winning goal, though Cillessen was unable to keep out Guedes' strike having got a hand on the effort.
Manchester City's Silva, who set up the goal, said: "I am very happy and very proud. It is my first title with Portugal. After the amazing season with my club, to finish this way is amazing. It is time to rest now and prepare for next season and try to do even better.
"The most important thing is that Portugal won. If you can add to that individual awards, then even better."
Portugal are now unbeaten in their last 10 games and despite defeat, Netherlands - who have failed to reach the last two major tournaments - will take heart from their progress since the appointment of Ronald Koeman as boss.
"They were masters at defending when they were ahead," said Koeman. "We should have been a bit more clever in looking for free kicks. We were not good enough tonight."
More about: Portugal Nations-League
