As of week 16 of the 2018 Super Rugby season, Ioane has scored seven tries in the competition. With the exception of the Blues' defeat to the Rebels on 2 June 2018, Ioane has played the full 80 minutes of every game for the Blues during the 2018 Super Rugby season. Despite being used out of position at Inside Centre multiple times during the season, Ioane was still the Blues' highest try-scorer in 2018, scoring 10 tries. His outstanding form in Super Rugby saw him retain his place as a regular starter for the All Blacks during the 2018 Steinlager series against France.
On 9 June 2018, Ioane scored two tries against France during the second half of the All Blacks' 52-11 victory at Eden Park. His second try, in the 74th minute, was intercepted from the French reserve hooker Adrien Pélissié 80m out from the tryline. Although French winger Teddy Thomas almost caught up to Ioane, Ioane still managed to score. Ioane played the full 80 minutes of the second test, on 16 June and had an outstanding defensive performance, although he failed to make the same impact on attack, with reserve first-five-eighth Damian McKenzie finding it difficult to control the game and distribute the ball to Ioane.
On 23 June 2018, having already been phenomenal defensively during the first half, Ioane scored the first hat-trick of his international career, in the second half of the final test of the Steinlager series, as the All Blacks beat France 3-0 in the series, winning the final test 49-14 at the Forsyth Barr Stadium in Dunedin. Ioane was the first All Black to score a hat-trick in over two years, when former All Black Julian Savea scored the final hat-trick of his career against France when the All Blacks beat them 62-13 during the 2015 Rugby World Cup. Ioane scored his three tries against France in the space of only 12 minutes, with Damian McKenzie setting Ioane up for his first and third, while Vice-Captain Ben Smith set Ioane up for his second. Ioane managed to beat four French defenders when he scored his first try, despite the defenders being in front of Ioane. Ioane finished the Steinlager series having played the full 80 minutes of all three tests against France, as well as the highest try-scorer of the competition. Ioane lost out on the award for Man of the Match to outstanding lock Scott Barrett.
Ioane played in four tests during the All Blacks' end-of-year tour in 2018, including the third Bledisloe Cup test against Australia, where he was named Man of The Match.