[1] In 2009, Todd made his Air New Zealand Cup debut representing Canterbury as a replacement against Waikato at AMI Stadium.

Todd made his international debut for them during a 24–9 victory over France on 22 June 2013, replacing fellow rookie Sam Cane off the bench in the 72nd minute.

After missing international rugby in 2014, Todd played against Samoa in Apia, in 2015, replacing veteran Jerome Kaino the bench for a one-off test match, which the All Blacks won, 25–16.

Todd earned the first two starts of his international career in the series, against South Africa and Australia, where New Zealand retained the Bledisloe Cup.

He was notably named Man of the Match in the final Bledisloe Cup Test, before being replaced by Ardie Savea in the 65th minute, as the All Blacks beat Australia 37–10.

After Jerome Kaino paused his training with the All Blacks for personal reasons and went to represent Auckland in the Mitre 10 Cup, Todd was re-selected and started against Argentina in a scrappy 36–10 win where he received the first yellow card of his test career and was replaced by Ardie Savea in the 65th minute.

Todd was later chosen as Crusaders' Player of the Season by his team-mates as the team beat the Lions, in the Super Rugby final, for the second year in a row.

After the conclusion of Super Rugby, Todd signed a high-profile one-season deal with Japan-based club, the Panasonic Wild Knights.

[5] Todd missed the 2018 Rugby Championship with his commitments to the Wild Knights, but was called in for the injured Sam Cane for 2018 the end-of-year tour.

With Liam Squire opting out of consideration for All Black selection, Todd went on to start against South Africa in the 2019 Rugby Championship, also appearing as a substitute against Australia in the first Bledisloe Cup test of the year, which was a 26–47 loss.

All Blacks Head Coach, Steve Hansen named Todd in New Zealand's 31-man squad for the 2019 Rugby World Cup on 28 August 2019.

[8] Although Todd was ruled out of the semi-final loss to England through injury, he played his last test for New Zealand on 1 November 2019, replacing Shannon Frizell, with 20 minutes left of the 40–17 win against Wales, during the World Cup's Bronze Final.