Simon Bramhall, 53, was given a community order and fined £10,000 after admitting two charges of assault.
During sentencing, the judge said he had “betrayed the trust” of patients.
Prosecutors described how the surgeon used an argon beam to brand his initials on the livers of two anaesthetised patients at the end of transplant operations in February and August 2013.
One of the livers failed – for reasons unconnected to Bramhall’s actions – and it was then that another surgeon discovered the initials “SB” burnt on to it and took a photo of the 4cm mark.
Bramhall, who is world-renowned in his profession, resigned from his job at Birmingham’s Queen Elizabeth Hospital in 2014.
One of the victims was left feeling “violated” and still suffers extreme psychological difficulties, Birmingham Crown Court heard.
In a victim impact statement, she said the moment she was shown the mark “will forever be etched on my mind”.
A nurse who witnessed the surgeon’s actions said she had asked him what he was doing; he is said to have replied: “I do this.”
The court heard Bramhall later told police he had “flicked his wrist” and made the mark in a few seconds.
“He knew that the action could cause no harm to the patient. He also said that in hindsight this was naive and foolhardy – a misjudged attempt to relieve the tension in theatre,” said prosecutor Tony Badenoch QC.
Judge Paul Farrer QC sentenced Bramhall to a 12-month community order with 120 hours of unpaid work, and fined him £10,000.
He told him: “I accept that on both occasions you were tired and stressed and I accept that this may have affected your judgement.
“This was conduct born of professional arrogance of such magnitude that it strayed into criminal behaviour.
“What you did was an abuse of power and a betrayal of trust that these patients had invested in you.
“I accept that you didn’t intend or foresee anything but the most trivial of harm would be caused.”
Sky’s Tom Parmenter, in court for the sentencing, said a “significant number of other former patients of Simon Bramhall were in court to show their support and gratitude”.
Bramhall was also described in mitigation as “one of the outstanding surgeons of his generation”, Parmenter added.
One of the patients supporting the surgeon was Barbara Moss, who was given just three months to live in 2006 when Simon Bramhall told her he would operate on a 15cm tumour.
“It was Mr Bramhall who gave me my first instincts of hope,” she told the court.
Military surgeon Colonel Douglas Bowley also paid tribute to the work Bramhall has carried out on injured service personnel returning from the war in Afghanistan.
Bramhall collaborated with Army doctors to drastically improve survival rates from the conflict.
The surgeon was given a formal warning by the General Medical Council last February and now works as an anaesthetist at a hospital in Hereford.