Objectives Despite the high prevalence of mental disorders among youth (age 12 to 17) and emerging adults (age 18 to 24), few receive mental health (MH) services. Using a cross-sectional study design, we examined population characteristics associated with MH service use in this age group from 2011 to 2016. Methods Data were from six cycles of the Canadian Community Health Survey (2011–2016). Population characteristics associated with service use were analyzed using logistic regression models for each year. Changes in odds ratios over time were used to examine trends. Results Presence of a mood or anxiety disorder had the largest magnitude of association on MH service use in every year. Trends suggested an increased association size between self-rated MH status and service use; lower self-rated MH was associated with a 62% increase in odds of service use in 2011 and an 83% increase in 2016. Being female was associated with increased odds of MH service use (range: 59–107%). Compared with white respondents, individuals who were East and Southeast Asian or South Asian had decreased odds of MH service use. While the association size varied for South Asians, there was a trend toward decreasing likelihood of accessing care (55% decreased odds in 2011, 74% in 2016) for East and Southeast Asians. Conclusion Trends suggest changes in population characteristics associated with access to MH care (e.g., self-rated MH status) as well as persistent inequity in MH service use in Canada for males and individuals from Asian ethnic groups.