Most of the money donated to Reclaim came from Brexit-supporting investment manager, Jeremy Hosking.
Mr Hosking is thought to have donated up to £5million to the party.
Mr Fox, a lockdown sceptic and anti-woke campaigner, claimed politicians have “lost touch with the people” before announcing his candidacy for London mayor.
The Lib Dems’ received £1,278,073.
The figures also show that of Mr Fox’s donations, £1million came from two individual donations, with the rest made up of 16 smaller sums.
Data shows that the Conservatives were by far the biggest recipients of donations receiving just under £6.5million over the first quarter.
Peter Cruddas, a Tory peer and banker, was the party’s biggest individual donor.
Labour secured £2.44million, with the Unison union named as the leading contributor.
Candidates have to achieve five per cent of first-preference votes to have the money returned.
The money will be retained by London Elects and used to offset the costs of running future elections.