The Manchester-born youngster made his Under-21s bow during a Premier League 2 clash against Aston Villa in February 2026 before netting his first goal at second-string level during a 3-0 win against Fulham.
Mills was handed his debut for England at Under-17 level in March 2026, starting in a 3-0 win against Faroe Islands at St. George's Park.
Primarily a left winger, Mills was named in a Premier League matchday squad for the first time during Newcastle's 2-1 win against Hull City in September 2026.
The 17-year-old was handed a first international call-up at Under-18 earlier this season, scoring on his debut in a 3-2 win against Colombia before scoring again three days later in a 2-1 victory against Egypt.