The 58-year-old quit the board of directors at Elland Road this morning, beginning a 79-day ban as owner of the club.
Cellino was forced to cut his ties with Leeds temporarily after losing an appeal against a Football League ruling disqualifying him from running the Championship side.
The ex-Cagliari owner has been banned by the governing body over a conviction for tax evasion imposed on him in Italy last year.
His appeal against the League’s decision was rejected by a Professional Conduct Committee on Monday.
Cellino, whose British firm Eleonora Sport Limited holds a 75 per cent stake in Leeds, is banned from exerting any control over the club until the second week of April, by which time his tax conviction will be spent under UK law.
In a statement, the Italian said: “It is with great sadness and frustration that I have to take this step, however I abide by the Football League’s decision to temporarily disqualify me from this great football club and will return in April in good health and good spirits.
“I have done my best for a club and fans that I hold close to my heart and it is now financially much stronger than it has been for a long time. It will continue to thrive and I am sincerely looking forward to returning very soon.”
United have named Andrew Umbers - a club director and the financier who arranged the sale of Leeds from Ken Bates to Gulf Finance House in 2012 - as temporary chairman in Cellino’s absence.
Recently-appointed chief operating officer Matt Child will also handle day-to-day operations while Cellino serves his ban.
It is understood that Giorgio Altieri, a Rome-based lawyer who has acted on Cellino’s behalf in the Stadio Is Arenas criminal case in Italy, will act as a representative for Eleonora Sport throughout Cellino’s suspension.
Cellino bought a controlling stake in Leeds through Eleonora Sport nine months ago but his time as president of the club has been dominated by a continuous fight with the Football League.
The governing body tried and failed to block his original buy-out on the basis of Cellino’s tax conviction but Cellino forced his takeover through on appeal in April.
The League’s board voted to disqualify him again on December 1, however, after a written judgement from the court case in Italy strengthened its argument that Cellino had been guilty of a dishonest act and was in breach of its Owners and Directors Test.
Cellino fought that ruling again but a PCC panel of Tim Kerr QC and Football League board members Greg Clarke and Richard Bowker rejected his challenge after an appeal hearing in London last Thursday.
Cellino’s ban will run for 79 days and is due to end on April 10.
The League said in a statement: “The Football League has been notified by Leeds United that its President, Massimo Cellino, has resigned from his position in accordance with with the recent decision of the Professional Conduct Committee (PCC).
“The PCC determined that Mr. Cellino is disqualified from acting as a ‘Relevant Person’, as defined under Football League regulations, until 10th April 2015. Both Leeds United and Mr. Cellino are fully aware of The Football League’s requirements emanating from the PCC’s decision and we are currently working with the Club to ensure that these are achieved.
“In addition, a further misconduct charge against Mr. Cellino and the Club for failing to supply the Italian Court judgment to The Football League when it first became available will be heard by a Football Disciplinary Commission in due course.”