Conversion therapy is based on a belief that people with diverse sexual orientations or gender identities are abnormal and should be changed so they fit within hetero-normative standards.
She also strongly pushed back on senior National MP Simon Bridges' suggestions that banning conversion therapy was an attack on free speech.
"I personally do have a wider concern," he said of the policy on the AM Show this morning.
"That is freedom of speech. That is in a liberal society, in a tolerant society, we have been very tolerant of different views."
National leader Judith Collins has said National does not have a position on the subject of conversion therapy.
Ardern this morning said the banning of such a practice was "absolutely not" an attack on free speech.
"We know that conversion therapy has a harmful impact on our rainbow community.
"We know that we have higher rates of self-harm and suicide in that community. So I consider that we have an obligation to fix this issue and reduce harm."
Ardern said the Government was already working on the policy at the moment – "we have committed to doing it".
"We're working on the policy now, we will be going out and consulting with communities who are deeply affected by this over the coming months.
"But I want to see that legislation in the House this year."
Earlier today, the Green Party's rainbow communities spokeswoman Elizabeth Kerekere criticised the Government for "dragging" on banning the practice.
She said places like the Australian state of Victoria has already a ban in place, having campaigned on it ahead of their election.
"We should be a leader - we'll be pushing the Government on this."
Banning conversion therapy was a Labour Party election promise ahead of the 2020 election.
"We will pass a law to ban the harmful practise of conversion therapy. Conversion therapy is based on the misguided idea that people are wrong or broken because of their sexual orientation or gender identity," Rainbow spokesman Tāmati Coffey said at the time.
"This is fundamentally wrong."
But this morning was the first time Ardern put a timeline on the legislation itself.