The COVID pandemic brought to light the pressing issues of social isolation and loneliness for older adults. Immigrant older adults’ experience of loneliness is even more exacerbated by factors, such as, language barriers, and the loss of cultural community. Key determinants of loneliness in older immigrants are not clear in the literature. A cross-sectional study was conducted in nine cities across Canada to: describe the experience of emotional, social and overall loneliness; and examine the determinants of loneliness among Punjabi, Mandarin, and Arabic-speaking older immigrants. A total of 647 older immigrants participated in the study. Descriptive statistics were used to describe their experience of loneliness, and multiple regression analysis was performed to examine the determinants of loneliness. Most participants had a post-secondary education, were married, and had been in Canada for about 16 years. On average, the participants reported good physical and mental health, and moderate levels of emotional, social, and overall loneliness. Ethnocultural group, emotional wellbeing, and depression were associated with emotional loneliness. Social loneliness was associated with education, depression, psychological distress, age, and ethnocultural group. Determinants of overall loneliness were age, gender, ethnocultural group, self-rated mental health, emotional wellbeing, depression, and psychological distress. Community based interventions that target these key factors must be designed to address loneliness experienced by older immigrants.