The former England and Nottinghamshire cricketer is expected to commence a two-year stint as president next month, according to BBC Sport.
The 53-year-old, who is father to England bowler Stuart Broad, racked up 25 Test appearances in his career and is also a Test match referee.
The PCA chief executive Angus Porter has spoken out about Botham's decision to step down.
"Sir Ian has been a generous and active supporter of the PCA, and it has been a privilege to work with him," he said.
"We are grateful for everything he has done for us, and offer him our very best wishes as he continues to dedicate his energies to his media career and his formidable charitable efforts."
The 55-year-old former England Test captain has raised millions of pounds for various charities, including Leukaemia Research.