Howard, 50, is the founder of Beechdean Motorsport and local ice cream company Beechdean Dairy Farmhouse.
The new board member won the British GT3 title last year in an Aston Martin V12 Vantage.
Howard said in a statement."There has been a tremendous amount of hard work done over the last couple of years and I am looking forward to being part of the development and growth going forward,"
Wycombe chairman Don Woodward added: "Having Andrew join the board gives us a better balance and allows the further development and growth of the club.
"This is a very exciting appointment and we all look forward to working closely with Andrew."
Wycombe avoided relegation on the final day last season finishing above Bristol Rovers on goal difference.