The last leaders' debate will screen on Wednesday at 7pm.
The NZ Sign Language version will be made available two days later, on Friday morning, via the OnDemand stream.
The delay would allow for a day-and-a-half turn around and high quality interpretation, Deaf Aotearoa chief Lachlan Keating said.
"The fast pace and quick fire nature of political debates presents a big challenge for live interpreting,'' he said.
There would be three NZ Sign Language interpreters involved - one interpreting for English, one for Ardern and one for debate moderator Mike Hosking.
Kenrick acknowledged International Week of the Deaf - which starts today - and how pleased TVNZ was to be playing a role in offering more viewing options for deaf and hard-of-hearing viewers.
The Human Rights Commission has also praised the announcement, with disabilities rights commissioner Paula Tesoriero calling the move a "significant outcome''.
"The ability for deaf New Zealanders to participate in the democratic process will be strengthened by this development.
"This is a step towards including more NZ Sign Language in television.''