Ahead of his appointment Mr Varghese was the firm's social justice and class actions principal.

Mr Tucker will remain at the firm but will take up a senior management role from April 21 when Mr Varghese takes over as CEO.

Maurice Blackburn chairman Steve Walsh thanked Mr Tucker for his service and commitment to the firm.

"Under Greg's leadership our firm has almost quadrupled the size of its staff, as well as seen an increase in offices opened through the significant organic growth of our business," Mr Walsh said.

Mr Walsh said Mr Varghese was a litigation funding expert and a successful class action lawyer.

"He has a long history with our firm, including most recently heading Maurice Blackburn's social justice practice, where he has run many of our most well-known pro bono cases including leading a legal campaign that successfully secured the release from detention of 111 Australian-born babies and their families," Mr Walsh said.

Mr Varghese said he was looking forward to leading the next chapter of the firm's growth and development.

"I am passionate about helping people who otherwise would not have access to justice," Mr Varghese said.

"For the rule of law to be meaningful, everyone has to have the ability to bring matters before the courts, not just the rich and powerful," Mr Varghese said.