He joins the board consisting of four executive directors and seven non-executive directors under the leadership of chairman Robin Smith.
Platts, a chartered accountant, commenced his working career in 1975 with Touche Ross, which later became Deloitte. He became audit partner and practice senior partner for the North East in 2002, and was based in Leeds until his retirement from Deloitte in 2008.
Platts is currently a non-executive director and chair of the audit and risk committee for A J Bell Holdings Ltd, the largest privately owned SIPP provider in the UK.
Platts said: "I have advised at board level on a wide range of financial, commercial and governance issues for more than 20 years and I am delighted to be joining the board of Leeds Building Society.
“Leeds has played an important part in my career and both my son and daughter study in the city at the College of Music and University respectively.”
Robin Smith, the society’s chairman added: "This is an excellent appointment and I am delighted to welcome Les to the board. His skill and expertise will help us to build on our financial strength and enable us to continue to deliver outstanding results."
