Alexandre "Sacha" Gaydamak (Hebrew: אלכסנדר גאידמק, born May 1976 in France) is a French and Israeli businessman. A member of the wealthy Gaydamak family, he is the son of Arcadi Gaydamak.
In January 2006 he announced that he was following his father into association football club ownership by becoming co-owner of English Premier League club Portsmouth F.C. with Milan Mandaric.
His father is the owner of Israeli side Beitar Jerusalem. In July 2006 Alexandre Gaydamak became the sole owner of Portsmouth, although Mandaric remained at the club as non-executive chairman until later that year. Gaydamak owns a Luxembourg-based company, Belvia S.a.r.l. and a British Virgin Islands company, Devondale Investments, which owned Portsmouth F.C.
On 21 July 2009, Gaydamak agreed to sell Portsmouth F.C. to Sulaiman Al Fahim in principle, and therefore stepped down from the board. He remained the owner of the club until the details of the sale had been finalised on 8 June 2009.
Gaydamak has been alleged to have asset stripped Portsmouth F.C. before this sale and yet still retains a claim, said to be £32,000,000, against the club as a creditor despite the huge debts at the club. Investigations into these allegations are ongoing.
On 22 October 2010 Gaydamak's business acumen came into question after reports of him demanding a payment from his former club Portsmouth for an apparent £2.5million. It seems that he was unsure that his unpaid debt would be repaid. The case was made more embarrassing after Portsmouth F.C had received confirmation several times from Gaydamak himself that the terms were agreed and that he was a secured creditor meaning that not only would be paid in full, but he would also be paid before many unsecured creditors who are set to only receive 20% of any debt.