"My manners are perfect, unlike yours," the conductor replies, to which the woman says "oh no they're not, in your country they're not, they're disgraceful".
"What does my country have to do with it?" the conductor asks.
It is unclear from the video what started the altercation, which was filmed on the Wellington to Johnsonville line, but a Metlink spokesperson said the argument began when there was a problem with the woman's ticket, which the conductor was trying to explain and find a solution for.
In the two and a half minute clip, members of the public interrupt to stand up for the conductor, with one woman asking her to "resolve it without being racist".
The woman repeatedly asks for her ticket, and when the conductor hands it over she begins to say "thank you Jesus" repeatedly.
She then appears to say "you will be crucified for your [unintelligible]."
"Clearly you're not a Christian and you don't know what it means to be a Christian," the conductor says.
Other commuters join in to challenge her comments, telling her "keep your mouth shut, we're all listening".
Another man addresses the conductor, telling him "what she said, we don't go with".
The woman then says she is Tūhoe and will "shut all these trains down".
"I own half this country you mother f******."
The conductor can be heard moving on down the train and saying to someone else, "it's just ignorance".
The woman says she doesn't "kiss people's asses, I speak the truth".
Metlink Wellington has responded to the video online.
"Kia ora Corey, this is very shocking to see. We would like to say thank you to the customers who have reported this incident. The Rail Operator have been made aware to address and hopefully prevent this type of behavior on all Metlink services. Kia kaha."
Taslim Parsons said her husband was one of those who stood up for the conductor.
"He was really upset when he got home," she told the Herald.
"He was pleased I wasn't on the train with him. As a person of colour I've put up with this stuff quite a lot.
"We've always kind of said that we would stand up - we have to."
Twitter users are also condemning the behaviour.
"I was there too. The train conductor behaved impeccably. It was quite confronting to see such intimidating and racist behaviour from the passenger," said one man.
"Disgusting. How dare she bring Taranaki into this poisonous korero. I am from Taranaki and this is NOT who I am. NO MANA," said another person.
Metlink told NZME in a statement one of their on board staff members was "subject to racial abuse" on the Johnsonville service last night.
"We applaud the way our staff member approached the situation and we have spoken to him to ensure that he has the support he requires following the incident.
"We would also like to thank the passengers on board for coming forward in support of our staff member, your kind words have been passed on to our staff member.
"Metlink does not condone any racist behaviour."