"I'm delighted to make our final board appointments," Richard Thompson, the ECB chair, said. "We have a strong and diverse board with extensive experience and a wide range of skills.
"Ebony is a unique talent, a trailblazer who was a winner on the pitch and has achieved so much off it. Her ACE programme has already made a huge impact in creating opportunities for youngsters from Black communities, and she shares my impatience for making further progress in creating a truly inclusive sport.
"Pete also brings with him a vast amount of cricketing experience along with invaluable insight in other sports. He is steeped in the recreational game, and will be another huge asset to the board.
"I'm also delighted that Katie Bickerstaffe has been appointed as senior non-executive director. Katie has already made a huge contribution over the past three years, utilising her experience from a number of different senior roles along with her passion for growing the game."
Rainford-Brent, who worked with Thompson while director of women's cricket at Surrey, was the first black woman to play for England and part of the teams that lifted the World Cup and World T20 in 2009, winning 29 caps between 2001 and 2010. Since retirement, she has worked as a broadcaster for the BBC and Sky Sports.
Ackerley is currently chief executive officer of the British American Football Association, and has previously served on the ECB's participation and growth board, as well as working with Lancashire Cricket Foundation, the Lord's Taverners, the England and Wales Cricket Trust and the Football Association. He is also a former head of development at the ECB.
The appointments, which are set to be ratified at Wednesday's Annual General Meeting, will fill vacancies arising from the death of Brenda Trenowden, Jim Wood's departure after reaching his maximum time on the board, and Valerie Amos, Martin Darlow, Barry O'Brien and Lucy Pearson not seeking re-election.