Dagg played international rugby for New Zealand's All Blacks from 2010 to 2017, before repeated knee injuries cut his career short.

Dagg announced his retirement from rugby on 4 April 2019 in an Instagram post citing continued issues with an injury to his right knee.

[citation needed] Coach Graham Henry decided to rest him for the second test against Wales, giving veteran Mils Muliaina an opportunity.

[citation needed] Dagg's second test try came in dramatic circumstances against South Africa on 21 August 2010 at FNB Stadium near Soweto, Johannesburg.

Regular right wing Ben Smith was used to cover Dagg's injuries and played so well that he took the fullback jersey for the first two Bledisloe tests.

Dagg was the given another shot against Argentina in his home province and played well enough to shift Smith back to right wing for the rest of the rugby championship.

Against England on the end of year tour, Dagg got shown up on defence by Jonny May and lost his fullback spot to Smith for the last test against Wales.

Dagg's latest injury required shoulder surgery, ruling him out for the rest of the Magpies' Mitre 10 cup-winning year.

Due to an injury to Nehe Milner-Skudder and his great form for the Crusaders (5 tries in his first 5 games), Dagg was then re-selected for New Zealand, being named in the 32-man squad for the All Blacks' three-match series against Wales.

He cemented his place as the All Blacks' first choice right wing, completing his comeback by finishing the competition as the joint highest try scorer with Ben Smith.

Dagg finished 2016 as the highest try-scorer of the year for the All Blacks, beating the team's new first-choice fly-half and World Rugby Player of The Year- Beauden Barrett and Ben Smith by one try.

Despite missing a chunk of the Crusaders' Super Rugby winning campaign due to knee surgery in 2017, Dagg was retained as the first-choice right winger for the All Blacks' series against the British and Irish Lions and Pasifica Challenge against Samoa.

Dagg started the third test on the wing again as he surpassed Jonah Lomu and Sir John Kirwan as the second-to-most capped All Blacks winger, second only to former teammate Joe Rokocoko.

In July Dagg signed a short term contract for Canon Eagles in Japan ruling himself out for the All Blacks for the rest of 2018.

Plagued by a long term knee injury which had prevented him from starting the season, Dagg received medical advice to hang up his boots.

In 2015, he appeared in a Men in Black themed safety ad for Air New Zealand with singer Stan Walker and actor Rip Torn.