Isaac John (born 12 December 1988) is a former New Zealand professional rugby league footballer who previously played for the Mount Pritchard Mounties in the Intrust Super Premiership.

In 2007 he appeared in the NSWRL Premier League for the Auckland Lions as well as playing for the Stallions in the Bartercard Cup.

In 2008 he played for the Junior Warriors in the inaugural Toyota Cup and Otahuhu Leopards in the Auckland Rugby League competition.

[2] John currently is the creative director and co-owner of the clothing brand YKTR[3] (You Know The Rules) which was founded in 2016[4] with former Brisbane Broncos player James Segeyaro and St George Illawarra Dragons player Corey Norman, and the trio went on to form another business named YKTR Sports[5] in 2019.

In Round 13 against the St. George Illawarra Dragons at Mt Smart Stadium, John scored his first NRL career try in the Warriors 22–20 loss.

John played in one match for the New Zealand Warriors in the 2011 NRL season in Round 2 against the Wests Tigers in a 20–12 loss at Leichhardt Oval.

[12] In 2011 John was named in the Cook Islands side but the Test was cancelled by the New Zealand Rugby League.

John represented the Cook Islands in the 2013 World Cup, playing in all 3 matches at halfback and scoring a try in the tournament.

[21] A week after making his international début for New Zealand, John has had his season cut short by suffering a season ending anterior cruciate ligament (ACL) knee injury while going down in a tackle in Penrith's NSW Cup win over the Newcastle Knights.