The Code does not provide a definition of discrimination. Instead, the understanding of discrimination has evolved from case law. To establish prima facie discrimination (discrimination on its face) under the Code, a claimant must show that:
- they have a characteristic protected from discrimination
- they have experienced an adverse impact within a social area protected
- by the Code, and the protected characteristic was a factor in the adverse impact.
The claimant must show that discrimination occurred on a “balance of probabilities,” that is, it is more reasonable and probable than not that discrimination took place. Once a prima facie case has been established, the burden shifts to the respondent to justify the conduct within the framework of the exemptions available under the Code (e.g. bona fide requirement defence). If it cannot be justified, discrimination will be found to have occurred.
Discrimination does not have to be intentional. Intent is irrelevant for establishing that discrimination occurred.
Discrimination is often hard to detect. Direct evidence pointing to discriminatory motives may not be available. Human rights decision-makers have recognized that cases may be shown through an analysis of all relevant factors, including evidence that is circumstantial. As well, human rights case law has established that a Code ground need only be one factor, of possibly several, in the decision or treatment for there to be a finding of discrimination.
The analysis of whether substantive discrimination has taken place should be flexible and look at the full context of the impact of the distinction on the affected individual or group. The contextual factors and relevant considerations may vary slightly based on the type of discrimination claimed (direct, adverse effect, systemic, profiling, etc.), or the ground alleged. However, the legal test and threshold for discrimination do not change.
It is not necessary for language or comments related to a disability to be present in the interactions between the parties to show that discrimination has occurred. However, where such comments have been made, they can be further evidence that the disability was a factor in the person’s treatment.
 See Moore, supra note 6; Peel Law Association v. Pieters, 2013 ONCA 396 (CanLII). Note that in a few cases, most of which have challenged government services or have raised concerns that different treatment may not amount to discrimination in a substantive sense, disadvantage has not been inferred or assumed from the circumstances but may have been required to be shown by the claimant to establish adverse treatment or impact: see, for example, Tranchemontagne, supra note 46; Peart v. Ontario (Community Safety and Correctional Services), 2014 HRTO 611 (CanLII); Ivancicevic v. Ontario (Consumer Services), 2011 HRTO 1714 (CanLII) [Ivancicevic]; Klonowski v. Ontario (Community Safety and Correctional Services), 2012 HRTO 1568 (CanLII). However, the Court of Appeal for Ontario and the HRTO have noted that in most cases under the Code, disadvantage can be assumed where there is adverse treatment based on a prohibited ground and that in most human rights cases it will not be necessary to go through a process of specifically proving what the disadvantage is: Tranchemontagne, supra note 46 and Hendershott v. Ontario (Community and Social Services), 2011 HRTO 482 (CanLII) at para. 45.
 Quebec (Commission des droits de la personne et des droits de la jeunesse) v. Bombardier Inc. (Bombardier Aerospace Training Center),  2 SCR 789, 2015 SCC 39 (CanLII); Gray v. A&W Food Service of Canada Ltd. (1994), CHRR Doc 94-146 (Ont. Bd. Inq.); Dominion Management v. Velenosi,  O.J. No. 1277 at para. 1 (C.A.); Smith v. Mardana Ltd. (No. 1) (2005), 52 C.H.R.R. D/89 at para. 22 (Ont. Div. Ct.); King v. CDI Career Development Institutes Ltd. (2001), 39 C.H.R.R. D/322 (Sask. Bd. Inq.); Wilson v. Solis Mexican Foods Inc., 2013 ONSC 5799.