Mr Gardiner was previously head of origination, corporate bank at ANZ, according to a statement by Findex. The latest appointment expands Findex's leadership team to seven individuals.
Findex chief executive Spiro Paule said Mr Gardiner is an exceptional business person with a background in banking, accounting and financial planning.
"Peter has deep experience in both 'big fours'. He held senior a position at the ANZ Bank for the past five years, and prior to that was with Ernst & Young in a senior client-facing position," he said.
"His experience across the three financial advisory sectors equips him with a skill set appropriate for our business as we roll out a unique, holistic financial services offering from all Findex brands.
"Peter has a passion for business that is built on his belief that success is driven by championing the client."