Allardyce, 58, revealed that he was close to agreeing an extension to his current deal after guiding the east London club to Premier League safety in their first season back in the Premier League.
And Gold wrote on Twitter: “I am delighted to announce that our manager Sam Allardyce has signed a new two year contract.”
Allardyce, who has been in charge of the Upton Park outfit since June 2011, was expecting to sign a new deal next week.
“We are getting ready to travel on Saturday and we are concentrating on Everton,” he said on Friday. “But by early or next midweek I will be looking to put pen to paper.
“There were processes we had to go through and put it together in the right way, which it has now. I never thought there would be any problem – and there hasn’t.
“There has been some issue with the legal jargon in the contract which I couldn’t understand so that has to go to both sides lawyers to agree and then it gets signed. The size of a manager’s contract is pretty substantial in terms of responsibilities.”
West Ham are currently eight points above the relegation zone in 10th place ahead of Sunday’s trip to Everton.