Grounds, who resigned from the RSPCA in April after nine months as deputy CEO, has worked in marketing and communications for charities including the NSPCC and Barnardo's.
He has set up his own strategic brand, marketing and communications consultancy, and plans to work for public, private and voluntary sector organisations that have the common goal of "trying to achieve social impact".
Grounds said too many organisations talked about integrating marketing and communications but failed to act on it.
"Now everyone talks about integrated comms, marketing, campaigning and fundraising, and it has become the common language in our world.
"That is a good thing and wasn’t the case ten years ago, but for too many organisations it is words rather than actual integration. It’s not just about using the same logo across the company, and it’s not straightforward, but those that do it reap the benefits."