On 14 February 2019, Owen travels to England to sign for Northampton Saints in the Premiership Rugby ahead of the 2019-20 season, where he will play alongside his brother Ben Franks at Franklin's Gardens.
Coming off the back of an injury-plagued Super Rugby season, Franks played two tests in his final season in New Zealand, taking part in the 2019 Rugby Championship for the tenth time. After a poor performance against Australia, in a record 26-47 defeat, Franks was axed from the match-day 23 for the second Bledisloe Cup test. On 28 August 2019, Franks was dropped from the All Blacks, missing out on the 31-man squad for the 2019 Rugby World Cup, with Nepo Laulala, Atu Moli, Joe Moody, Angus Ta'avao, and Ofa Tu'ungafasi being the preferred props. Having signed for Northampton earlier in 2019, Franks’ shock omission from the squad effectively ended his decorated international career.