Speaking in Parliament, Ardern quoted Children's Commissioner Judge Andrew Becroft, who said it was "truly gratifying" to see political leaders rising above political differences to advance such a critically important piece of legislation.
"I am delighted we have achieved this," Ardern said.
"Reducing child poverty, as I've said many times in this place and outside of it, is one of the reasons I entered politics, and this bill has been one of the highest priorities of this Government.
"The essence of this bill is to build enduring political accountability, consensus and action on reducing child poverty. It provides a framework for measuring and targeting child poverty, and it creates a commitment to action on the part of the Government to address the wellbeing of all tamariki and rangatahi."
Ardern said there were very few things as vital as reducing child poverty.
"There are some things that we can take the politics out of, some of the time, and I think this is one of those occasions. But, the next steps are the important ones and this coalition Government is absolutely committed to putting in place the fundamental changes that are needed to build, first and foremost an inclusive and sustainable economy, one that delivers greater prosperity to all its people," Ardern told Parliament.
Alfred Ngaro, National's spokesman for children, said National had achieved changes to the bill which created the right pathway for reducing child poverty.
But he lamented the demise of the social investment approach taken by the previous National government, largely absent from the bill.
"If we're going to challenge the system so that it changes, then social investment was actually doing that.
"How can we hold the system accountable? We believe that social investment was a way of being able to do that," Ngaro said.
National won some social investment-related concessions on the bill, including annual reporting on one or more child poverty-related indicators, having regard to principles of early intervention and evidence-informed policy when developing the strategy and setting out how the Government intends to evaluate the effectiveness of policies included in the strategy.
Ngaro finished his speech with a few bars of Bob Marley's Redemption Song, saying "none but ourselves can change our mind" and communities needed to stand up and declare that they also wanted to reduce child poverty.
Act leader David Seymour, who opposed the bill, said it would do nothing to solve poverty issues.
"If more money was the solution, the Government spending tens of billions of dollars a year in benefits, in Working for Families, in accommodation supplements, would have solved poverty by now.
"All this bill is going to do is tell us how many households are within 60 per cent, or 40 per cent or 50 per cent of median income. It is not a measure of poverty," he said.