Ardern is expected to answer questions about their meeting when she fronts up to media for her post-Cabinet press conference this afternoon.
Last week a spokesman for Ardern confirmed today's meeting to the Herald, saying they would continue discussions on eliminating terrorist content from social media platforms.
The meeting was timely as Ardern prepares to head to New York next week to attend the United Nations General Assembly and follow up on progress on the Christchurch Call.
The call, a voluntary set of guidelines aimed at eliminating violent extremism and terrorist content from online platforms, has been signed by 17 countries, the European Commission, and eight online platform providers including Twitter.
Twitter is also one of five companies - along with Facebook, Amazon, Google and Microsoft - to commit to a nine-point plan to tackle digital harm.
Their meeting comes after Dorsey's account was recently hacked and used to send racist and vulgar tweets to his 4.2 million followers.
The tweets included messages such as "Hitler is innocent".
Twitter suspended accounts that the hacker or hackers retweeted while they had control of Dorsey's account, and temporarily turned off the ability to tweet via text message.
Ardern and Dorsey first spoke on the phone in April this year as she reached out to tech companies to gather support for the Christchurch Call summit in Paris.
They had a private one-on-one meeting for the first time in Paris in May in the days leading up to the Christchurch Call summit.