He was named in the one-day squad for the tour of England following the retirement of Daniel Vettori after the 2015 World Cup as New Zealand searched for another left-arm spin option.

He was handed his One Day International debut at Edgbaston having played just 19 List A matches for Northern Districts.

[4] Santner was bought by Chennai Super Kings in 2018 for ₹50 lakhs but due to a bone defect in his knee that required surgery, made his IPL debut the following year.

[15] For the 2016 World Twenty20 Santner was picked to the New Zealand squad as a premier spin bowler along with Nathan McCullum, who was playing his last international tour.

Santner bowled Pakistani cricketer Fakhar Zaman with a carrom ball, something he had been working on for some time, but only recently brought into his international repertoire.

In March 2018, Santner was out of the Test series against England, after suffering a knee injury, ruling him out of action for six to nine months.

[22] The injury meant Santner's planned spell in English county cricket with Derbyshire and Indian Premier League during 2018 had to be cancelled.

[25][26] In November 2019, while playing against England at Bay Oval, Santner scored his maiden test century.

[27] In November 2020 Santner led the New Zealand side for the first time in a T20 against West Indies at Bay Oval, Mount Maunganui.

[29] On 13 February, 2024, Santner is named as Captain for the T20 international series against Australia, with Tim Southee only available for Game 1.