Justice Christian Immer earned a Bachelor of Civil Law and a Bachelor of Common Law from McGill University in 1991, as well as a Bachelor in Secondary Education in History and Geography from the Université du Québec à Montréal in 2008. He was called to the Quebec Bar in 1992.

Prior to his appointment to the Superior Court of Quebec in 2019, he participated in founding the firm Sheahan LLP in 2011, where he worked until his call to the bench, representing clients primarily in the fields of environmental law and employment law. Justice Immer articled at Woods LLP, subsequently working there until 2005 in the areas of corporate and commercial litigation and employment law. He represented clients before the Quebec Superior Court, the Quebec Court of Appeal, the Federal Court and the Supreme Court of Canada, as well as before various administrative tribunals.

Justice Immer was appointed to the Superior Court on March 7, 2019, and elevated to the Quebec Court of Appeal on January 27, 2025.