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Jeffrey Mammon, AccFM

Jeffrey Mammon, AccFM

Senior Lawyer

As someone who loves to travel, Jeffrey has always been quite the adventurer. Although he has made many trips overseas, his travels closer to home have taken him whale watching off the coast of Nova Scotia and even glacier ice trekking in Jasper, Alberta.

Born in Toronto, Jeffrey received his Bachelor’s degree from York University, where he was a member of the Dean’s Honour Roll. Jeffrey moved out West and lived in Edmonton, Alberta where he attended law school at the University of Alberta and attained his Juris Doctor law degree. Jeffrey then moved back to Toronto where he was called to the Ontario Bar in 2001.

While an undergraduate student at York University, Jeffrey completed the Investment Funds Institute of Canada Mutual Fund Licensing Exam. So, before getting his law degree he started out at one of Canada’s largest mutual fund investment companies. After law school, he articled for a leading regulatory body overseeing the Canadian mutual fund industry.

Before joining Gelman & Associates, Jeffrey opened his own law practice as a sole practitioner and focused on civil litigation matters, with an emphasis on family law. He became a regular Duty Counsel panel member at the Family Courts. He also served as an Area Committee Member for Legal Aid Ontario.

As a lawyer, Jeffrey has a great talent for getting people talking so that they can reach a settlement, and he has extensive courtroom experience at the Superior Court of Justice and the Ontario Court of Justice. Fighting for the underdog is important to him, and he takes a hands-on approach to every case. You can count on him to listen to your needs and put himself in your shoes.

Jeffrey successfully completed the Family Mediation Certificate Program through York University and is an accredited Family Mediator through the Ontario Association for Family Mediation (OAFM).

An avid sports fan, Jeffrey always finds time to cheer on the Blue Jays, the Maple Leafs, and the Raptors.

Reported Cases:

  • Smith v. Porretta, 2020 ONCJ 653 (CanLII) – Issue of mobility/relocation allowing our client and their child to move residence from Brampton to London.
  • Paunov v. Paunov, 2014 CarswellOnt 16587; 2014 ONSC 353 – Matter dealt with importance of offers to settle and costs being awarded in favour of the successful litigant.
  • Children’s Aid Society of Toronto v. T. (A.), 2010 CarswellOnt 7788; 2010 ONCJ 456 – matter dealt with change of venue and statutory test of “preponderance of convenience”. Test of “substantial” convenience is more demanding that a test of “preponderance of convenience”. In any assessment of “preponderance of convenience” test, court must consider child’s best interests and not necessarily wishes or convenience of parties.
  • Solomos v. Mohammed, 2008 CarswellOnt 8584, W.D.F.L. 1089, ONCJ – Matter dealt with father’s request to have unsupervised access visits to the child and mother’s attempt to unreasonably deny the access.
  • Javan v. Shafiee, 2009 CarswellOnt 5025, W.D.F.L ONSCJ – Matter dealt with custody, access, child support and equalization of family property.
  • Ziaolhagh v. Torabi, 2009 CarswellOnt 653, ONCJ – Matter dealt with motion to remove other party’s lawyer from record due to conflict of interest and award of costs personally against opposing counsel.

Jeffrey Mammon, AccFM



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Federation of Asian Canadian Lawyers
Law Society of Ontario
Peel Law Association
UJA Federation of Greater Toronto
York Region Law Association
Collaborative Practice Simcoe County
Law Association Simcoe County
Widows & Orphans Fund