The Gateshead-born forward has joined National League outfit Hartlepool United, managed by former Sunderland and Leeds United manager Simon Grayson, on a permanent basis after impressing as a trialist.
The 19-year-old, who joined his boyhood club's Academy in 2019, will simultaneously join Dunston UTS, competitors in the Northern Premier League Division One East, on loan for the duration of the 2025/26 season.
Donaldson told Hartlepool's official club website: “I’m buzzing, to be honest. Coming in as a trialist, it was tough but all the lads made me feel welcome.
“I’ve played a few games and I thought I’d done alright, the support has been class as well and they’ve been really positive about my performances.
“This is in pre-season, too, so I cannot wait to see what it is like during the season.”