Brownsword attended The Harvey Grammar School in Folkestone and then trained as a chef.
He started the Andrew Brownsword Collection, a publishing business founded in Bath in 1971. Brownsword started by selling greeting cards to retailers like WH Smith from boxes and the back of his car.
In 1987, he agreed to market artist Deborah Jones Teddy Bear design, developing the Forever Friends genre in a flat above a Chinese takeaway in Reading, Berkshire in the early 1980s:
"I wanted to develop a teddy bear that appealed to adults as well as children. I based Forever Friends specifically on the teddy bear that Sebastian Flyte carried around in Brideshead Revisited. It became the bear found in the attic."
The success created a financial income to develop the Andrew Brownsword Group, based on greetings cards and associated gifts with a peak turnover of £65 million. The Andrew Brownsword Collection, Andrew Brownsword Gifts and the Gordon Fraser Gallery (the latter acquired in 1989), were acquired by Hallmark Cards in 1994 for an estimated £195 million. Brownsword became Chief Executive of Hallmark in Europe, a position which he held for four and a half years before leaving to develop other business interests.
Brownsword has used these monies since to develop both his business and charitable interests, buying stakes in:property development (The Bath Priory, Gidleigh Park in Devon, and Sydney House in Chelsea, London); ABode Hotels with chef Michael Caines (of which the Royal Clarence Hotel in Exeter was destroyed by fire in 2016); buying various businesses including Paxton & Whitfield cheesemonger in London and Snow and Rock; founding local radio station Bath FM with journalist and local resident Jonathan Dimbleby; and buying Bath Rugby.
In April 2010, Brownsword sold Bath Rugby to businessman Bruce Craig.
The Andrew Brownsword Art Foundation is a registered charity which aims to buy and loans works of art to mainly UK based museums. The collection includes works by Thomas Gainsborough.
He was appointed Commander of the Order of the British Empire (CBE) in the 2014 Birthday Honours for services to the arts, heritage, and health in Bath and South-West England.
Married to Christina, Brownsword has two daughters and lives in the week in London, and at the weekend in their various homes in the West Country. Brownsword enjoys skiing and sailing.
A methodist, having become heavily involved in The Prince's Trust, he is known to Prince Charles Brownsword sponsored the £1 million development of the markethall at Poundbury, designed by architect, John Simpson & Partners and based on early designs, particularly the one in Tetbury.
Brownsword's main second home is in Bath, and he has helped sponsor numerous local charities and organisations: Bath Preservation Trust, Bath Festival, RUH, Holburne Museum, and Bath Abbey. His renovated holiday home, Kittery Court in Kingswear, Devon, was destroyed in a fire caused by a plumber in April 2007.