The one-time owner and chairman of the Wetherby Road outfit and managing director at Elland Road passed away suddenly on Tuesday night while holidaying with family in Tenerife.
"It's a huge loss. Bill Fotherby will be fondly remembered by a lot of people," said Garry Plant, Town's managing director.
"What he did here was integral to the development of this football club.
"He was a fine custodian, someone who took the club on from where he found it and his work helped enable us to progress to where we are today.
"It shouldn't be forgotten that Bill was the man who employed Simon Weaver and gave him a chance when he had no prior managerial experience. Obviously that proved to be quite a decision."
A successful businessman, Mr Fotherby operated in the clothing industry before joining Leeds United's board of directors in 1978, helping transform the club's commercial fortunes.
Working alongside long-serving Whites chairman Leslie Silver, Mr Fotherby was instrumental in Leeds' rise from second division strugglers to first division champions.
Most notably, it was he who persuaded Howard Wilkinson, the manager who led United to two league titles, to swap Sheffield Wednesday for Elland Road in 1988.
Having left the club in 1996 following a brief stint as chairman, Mr Fotherby then arrived at Harrogate Town in 2000, taking over and revealing a desire to guide the Sulphurites into the Football League.
He oversaw promotion from the then-Unibond first division in 2002 and then into the newly-formed Conference North in 2004.
Current vice-chairman Howard Matthews joined Town's board in 2002 and worked closely with Mr Fotherby.
"Bill was really charismatic and a great person, there simply aren't characters like him anymore," he said.
"He was so passionate and enthusiastic about football. It was great fun working alongside him.
"He would always say that he was the same after a game, win or lose, but he definitely wasn't the same if we'd lost. He really didn't like losing.
"Bill did an awful lot for Harrogate Town. There was so much more interest in the club as a result of him being involved.
"He really will be missed."
In 2009, Mr Fotherby appointed a 31-year-old Simon Weaver as first-team manager, a position which he still holds today.
"I was a brave choice because I barely had any coaching experience, nevermind experience as a manager," Weaver said.
"I feel like I owe Bill a lot and I was really sad to learn of his passing.
"He was a one-off, a proper big character, lovable and a very warm man."
Mr Fotherby, who lived in Harrogate, handed over control of the club to Simon's father, Irving Weaver, in June 2011, staying on as chairman for five months before leaving Wetherby Road altogether in early November of the same year.
Joining those connected with Town in paying tribute to Mr Fotherby, Leeds' current majority owner Andrea Radrizzani Tweeted: 'RIP Bill. Truly honoured I have met you last year. Thank you for all you have done as custodian of this special club. Inspirational.'