Leighton was born in Regina, Saskatchewan, and grew up in the Kensington community of north Edmonton.  Leighton is a status Indian whose Great Grandfather was once the Hereditary Chief of the Carry The Kettle or Jack Band at Sintaluta, SK.  Leighton‘s grandmother and great aunt were both the notorious Brandon Indian Residential School survivors.  Leighton‘s father is a Treaty Indian who spent over two decades helping indigenous youth transition out of urban gangs, and was the founder of The Spiritkeeper Youth Society.

Leighton excelled in sports and academics, graduating with honours from Queen Elizabeth Composite High School in 1985. He scored the highest mark in the Province on the Social Studies departmental final examination and was awarded the Alexander Rutherford Scholarship.  He also played Bantam and Midget AAA hockey with the Canadian Athletic Club.  From 1985-89, he attended Augustana University in Camrose before transferring to the University of Alberta to complete his B.A. (Distinction) with dual majors in English Literature & History.  He was awarded an essay prize in Ethics in 1988 and received the Louise McKinney Scholarship, awarded to Alberta students with the top 2% of GPA in the Province.  Leighton was awarded the prestigious Legal Studies For Aboriginal People Scholarship from 1989-92; a national prize presented to only ten students each year.  He received early acceptance to the University of Alberta Faculty of Law in 1988 and graduated in 1992.  Leighton also pursued post-graduate degrees in Business Administration (2017) and most recently completed his Ph.D. (Philosophy) during the 2020 pandemic.

Leighton began his legal career with the Federal Department of Justice. He completed his Articles of Clerkship in 1993 before taking a hiatus to play minor league pro hockey with The Daytona Beach Sun Devils.  In 1995, Leighton resumed the full-time practice of law.  In 2005, Leighton founded his current practice.  Leighton was admitted to the Law Society of Saskatchewan in 2004 and to the Law Society of British Columbia in 2014.  Leighton has conducted hundreds of trials before Alberta Courts and has been considered one of Alberta’s top criminal trial lawyers for many years.  He has served as mentor or principal to eight articling students, two of whom became Partners in GWSLLP.  Leighton is also a Qualified Mediator and Arbitrator and a member of the ADR Institute of Canada.  He served as an Adjudicator in Law Society Disciplinary Hearings from 2015-2020.  Leighton was made Queen’s Counsel in 2010 and was then the youngest lawyer in Alberta to hold that prestigious designation.  He received the 2013 Stars of Alberta Volunteer Award, the 2015 Legal Aid Society Access to Justice Award, and the 2019 Alberta Civil Trial Lawyers Gary J. Bigg Justice & Humanitarian Award.

Leighton was heavily involved in the original IRS Class Action from 2004-2016, and represented hundreds of claimants in the ADR process that was part of the settlement, culminating in the Truth & Reconciliation Commission Report.  He and his wife, Jennifer, are the proud parents of two sons who attend Rink Hockey Academy in Kelowna, B.C.  Their family is also proud owners and supporters of the Drayton Valley Thunder Junior A Hockey Club.