Former Test off-spinner Tim May resigned from the role in early March, prompting a search for a replacment CEO.
The ACA said after an extensive interview process Marsh had emerged as the outstanding candidate for the position and would start work on July 1.
ACA president and former Test wicketkeeper Ian Healy said the ACA executive was delighted with Marsh's appointment.
"I am pleased to announce that Paul Marsh has been appointed to the role of chief executive of the Australian Cricketers Association," Healy said in a statement.
"We consider the role of ACA chief executive to be one of the most important and influential positions within the cricket community and it was essential that the role be filled by a person with a passion for the game and its players.
"Through his role as manager of member services and operations with the ACA, Paul has developed knowledge of the issues and built relationships with key stakeholders that will ensure he is an outstanding leader for the association."
Marsh is the son of former Australian Test wicketkeeper Rod Marsh and brother of Tasmanian captain Daniel Marsh.
Marsh, who holds a bachelor of commerce and is studying for an MBA, said he was looking forward to the challenge of heading the ACA in future dealings with Cricket Australia (CA).
"Having worked with the ACA and for Australias past and present cricketers for the last three and a half years, I am ready for and excited by challenges this role will bring," he said.
"My vision for the ACA is to ensure we make a genuine difference in the lives of our members."