The Club Licensing Benchmarking Report from European football's governing body, which covers the 2015 financial year, lists United's debt to be $759 million - significantly more than the next club on the list, Benfica, with $476 million.
United's figure is also an increase of 25 per cent on the previous 12 months, bucking trends across Europe of falling debts year-on-year for the past five years that UEFA attributes in part to its Financial Fair Play regulations.
Mounting debt under the stewardship of the Glazer family, who controversially bought the 20-time English champion in 2005, has long been a source of anger among significant sections of the Old Trafford fanbase.
UEFA's report seeks to place debt figures in context and the fact United's debt is broadly in line with its 2015 revenues of $738.5 million - the third largest in world football behind Real Madrid and Barcelona - and is 80 per cent of its long-term assets means it is not a high-risk case.
The worst-off clubs in this regard are Queens Park Rangers, now of the Championship, whose $395.5 million debt is 480 per cent of their long-term assets, and Fenerbahce, with $235.3 million at 610 per cent.
Additionally, the falling value of the pound has impacted upon United's debt, despite the club posting record revenues of $833.6 million this year.