Bannatyne received his OBE partly in recognition for his work with charities such as Mary's meals. He has funded several projects over a ten-year period in Romania, including Casa Bannatyne in Târgu-Mureş, a hospice for orphans with HIV and AIDS in which he invested £80,000. In March 2008, he established the Bannatyne Charitable Trust.
On 19 May 2008, Bannatyne added his support to the launch of the Geared for Giving Campaign at the House of Commons to encourage UK business leaders to set up and promote a Workplace Giving scheme to benefit UK registered charities with tax effective donations through employees' pay. He then helped to promote Clydesdale Bank's and Yorkshire Bank's efforts to promote the programme through ATM (Automated Teller Machine) rolls. "They are really going for it, over 20 per cent of their employees are giving money through this system", Bannatyne says.
On 29 August 2008, Bannatyne appeared on television programme Who Wants to Be a Millionaire?, raising £20,000 for charity NCH.
He became President of the charity No Smoking Day in October 2008. The charity runs the annual health awareness campaign – helping people who want to stop smoking. This followed on from him making a documentary about the ethics of British American Tobacco.
On appearing on the Question Time panel on 7 February 2008, he revealed having been a donor to the Labour Party under Blair. He also voiced his support for Brown, but criticised the Cabinet for what he described as "petty squabbles based on personal ambition". In March 2011, Bannatyne appeared to switch political affiliations again, by backing certain measures imposed in Chancellor George Osborne's budget even though he mocked the government a few months earlier.