He was NFU deputy president between 1992 and 1998 and then president between 1998 and 2004.
Gill was president during the BSE and foot and mouth crises of the late 1990s and early 2000s, and called for reforms to the Common Agricultural Policy in 2003.
He was appointed a CBE in 1996 and knighted in 2004.
NFU President Meurig Raymond said: "Ben Gill always had a big personality and tremendous determination.
"He led the farming industry through some very difficult times, but he always fought hard on behalf of the NFU’s farmer and grower members. Our industry will continue to benefit for a long time as a result of his achievements.
"Our sympathies are with his wife Lady Carolyn and his four sons."
Gill studied Agriculture at St John’s College, Cambridge before working in Uganda for three years where he established a working school farm, and a GCE ‘O’ level course. On returning to the UK he worked as a farm manager in East Yorkshire for two years before taking over the family farm in 1978.
He was also president of the Confederation of European Agriculture from 2000 to 2004 and a member of the Executive Committee of the World Body: International Federation of Agricultural Producers.
After retiring from the NFU he has established Hawkhills Consultancy and The Hawk Creative Business Park.
In 2005 he chaired the Government’s Biomass Task Force.
He was also a non-executive director of Countrywide Farmers plc, chairman of English Apples & Pears, chairman of Eden Research plc, chairman of Meritas Developments and chairman of Visit Herefordshire and a partner of W.N. Gill & Son. He was a governor of the John Innes Institute and a director of the Norwich Research Partners LLP at Norwich.