The 41-year-old local businesswoman, who owns the European arm of cosmetics firm Kroma, made her move after club owner Omar Khan decided to offer shares in the Bulls and it comes two months after Kate Hardcastle became their first female non-executive director.
A lifelong Bradford fan and mother of two, Willey has vowed to bring a touch of "glitz and glamour" to the club, and she said: "I've known Omar for a while and was delighted when he bought the Bulls."
She added: "I've always been very passionate about the club and have been helping out on a voluntary basis with ideas for drumming up corporate sales and have taken out a couple of advertising boards for my business at the stadium. This was done with a view to coming on board as a director and I'm really excited about it.
"I've known other people who have grown up in Bradford and done well for themselves but invested their money elsewhere.
"I'm happy to put my money into the club and help put Bradford back on the map because there has been enough doom and gloom in recent times.
"Rugby has been predominantly a man's game but I want to inject some glitz and glamour into the game and into the Bulls."
The deal, which is expected to be rubber-stamped within the next month, will still leave Khan as the largest stakeholder.
Bradford general manager Ryan Whitcut said: "It's fantastic news that Jay, a true Bradfordian, has voiced her intention to invest both time and money into the club.
"It has always been Omar's plan to make part of the Bradford Bulls available to the Bradford community and the supporters."