Arsenal manager Arsene Wenger and ex-Ipswich boss Roy Keane are ranked joint second, worth £29m, ahead of Manchester City's Roberto Mancini (£21m).
Another Italian comes in at joint fourth as Republic of Ireland boss Giovanni Trapattoni is level with Mancini on £21m.
As well as Keane, two more of Ferguson's former players make the top 10 with Hull boss Steve Bruce and former QPR manager Mark Hughes both amassing fortunes of £14m.
The fourth annual guide to the wealthiest people in British sport rates Lewis Hamilton, now worth £60m, an increase of £5m since last year, as the wealthiest British driver currently competing in Formula One.
Hamilton stays narrowly ahead of Jenson Button, who has also added £5m to his fortune in the last year and is now worth £58m.
Scottish motor racing driver Dario Franchitti, who is a four-time champion of the IndyCar series in America, is worth £50m, up £4m on last year.