Whelan bought the club a little over 20 years ago in February 1995 and was at the helm as the Latics enjoyed a meteoric rise from the fourth tier of English football to the Premier League.
The 78-year-old will continue to own the club but no longer have a hands-on role, while Oxford University graduate Sharpe, who was appointed a director at the DW Stadium in December, will be formally confirmed as chairman in the near future.
“The time has now come to hand over the reins,” said Whelan. “I am nearly 80 years old and spend an increasingly long time abroad, and cannot make it to games. It is a decision I have been mulling over for some years and I believe David is now ready.”
The outspoken Whelan was slapped with a six-week ban from all football-related activities in December after accepting a Football Association charge for making racist remarks about Jewish and Chinese people. Whelan, who broke his leg while playing for Blackburn Rovers in the 1960 FA Cup final, ends his tenure as chairman with Wigan 23rd in the Championship and nine points from safety.