A lifelong supporter of Chelsea Football Club, Attenborough served as a director of the club from 1969–1982 and between 1993 and 2008 held the honorary position of Life Vice President. On 30 November 2008 he was honoured with the title of Life President at the club's stadium, Stamford Bridge. He was also head of the consortium Dragon International Film Studios, which was constructing a film and television studio complex in Llanilid, Wales, nicknamed "Valleywood". In March 2008, the project was placed into administration with debts of £15 million and was considered for sale of the assets in 2011.
In the 1940s, he was asked to 'improve his physical condition' for his role as Pinkie in Brighton Rock. He was asked to train with Chelsea Football Club for a fortnight, subsequently becoming good friends with those at the club. He went on to become a director during the 1970s, helping to prevent the club losing its home ground by holding onto his club shares and donating them, worth over £950,000, to Chelsea. In 2008, Attenborough was appointed Life President of Chelsea Football Club.
In 2008, he published an informal autobiography entitled Entirely Up to You, Darling in association with his colleague Diana Hawkins.
In August 2008, Attenborough entered hospital with heart problems and was fitted with a pacemaker. In December 2008, he suffered a fall at his home after a stroke and was admitted to St George's Hospital, Tooting, South West London. In November 2009, Attenborough, in what he called a "house clearance" sale, sold part of his extensive art collection, which included works by L. S. Lowry, Christopher R. W. Nevinson and Graham Sutherland, generating £4.6 million at Sotheby's.
On 20 November 2008, Attenborough was awarded an Honorary Doctorate of Drama from the Royal Scottish Academy of Music and Drama (RSAMD) in Glasgow.