He was a major voice in the recent talks about getting the A-League going once more in amid the coronavirus pandemic.
A former player and a lawyer by profession,Didulica had spells working with Melbourne City in player and list management and also with the FFA.
PFA president Alex Wilkinson paid tribute to Didulica's devotion to Australia's footballers and his role in shaping the soccer industry for professional players during his tenure.
"'JD'came into the role of chief executive four years ago when the PFA was going through a difficult time. He galvanised the players and staff and pushed the organisation to new heights,"the former Socceroos centre back and Sydney FC captain said.
"During his time with the PFA,JD proved he is not only a great football administrator,but more importantly he is a great person who always put the players before anything else.
PFA executive member Lydia Williams,the Melbourne City and Matildas goalkeeper,said Didulica's dedication to embedding gender equality in the organisation's ethos had delivered incredible results for professional players.
"The work that JD has achieved and his vision for equality within the game in Australia between men and women has not only been realised through the national teams collective bargaining agreement last year,but also through the announcement of the 2023 Women's World Cup.