Community Matters, the representative body for community groups, will allow businesses, community organisers and community schools and colleges to become members.
The new membership category, which will be available from 21 June, comes after a six-month review on how Community Matters serves civil society.
Community Matters currently has a membership of more than 1,200, which includes local authorities, housing associations, community voluntary services and community organisations.
David Tyler, chief executive of Community Matters, said that businesses, smaller groups, experts and community organisers were contributing to improving their communities in common with traditional community groups, "albeit in slightly different ways".
"We now want to provide a supportive home for them too so we can work together to bring about our shared vision," he said.