Arsenal have appointed Sir Chips Keswick as their new chairman, with Peter Hill-Wood standing down for health reasons.
Hill-Wood, 77, and leaves after 51 years on the board.
He said: "Although I am feeling better I feel this is the right time for me to stand down."
Keswick, 73, said: "I am honoured. This is one of the great clubs in the game, recognised and loved by millions."
Hill-Wood had been chairman since 1982, with his grandfather, Sir Samuel, and father, Denis, the club's previous chairmen in a period stretching back to 1927.
Keswick, a director of the Bank of England, has been on the Arsenal board since 2005.
He told the club's website: "I am sad to see Peter standing down due to his health and we all hope he continues well in his recovery.
"The Hill-Wood family has made an extraordinary contribution to Arsenal over many decades. They have been central to the club's many achievements during this time.
"I am looking forward to leading the club to future success."