Baroness Karren Brady has stepped down from her position as vice-chair of West Ham after 16 years at the club, the Premier League side confirmed on Tuesday.
The 57-year-old is best known to the public for her role as an adviser to Lord Sugar on the BBC show 'The Apprentice.'
Her exit comes amid West Ham's battle to avoid relegation -- after Monday's draw at Crystal Palace, the east London club are two points above 18th-placed Tottenham Hotspur with five matches remaining this season.
Brady took up her role with West Ham after David Gold and David Sullivan bought the club.
She previously worked as managing director at Birmingham City after Sullivan purchased that club.
"It has been a privilege to work alongside the Board, management, players, staff and supporters at West Ham United," Brady said in a statement.
"Together we have achieved remarkable milestones, but the highlight for me will always be lifting the UEFA Europa Conference League trophy -- a moment that will stay with me forever.
"I am deeply grateful for the relationships, challenges and opportunities that have shaped my time at the club."
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During Brady's tenure the club completed their move from Upton Park to the London Stadium, which was built as the flagship venue for the 2012 Olympic Games.
Brady added: "While this chapter closes, my passion for football and commitment to supporting the next generation of leaders remains undiminished. I wish West Ham United every success for the future and look forward to following their continued achievements with pride."
Sullivan, the club's chair, described Brady as an "exceptional leader" and added: "We wish her every success in her future endeavours and thank her for her outstanding contribution over the past 16 years."
Information from PA contributed to this story.