Background: Outdoor learning offers clear physical, cognitive, social-emotional and academic benefits for children and yet, it is considered a grassroots approach to teaching and learning in elementary schools. Purpose: We examined teachers' perspectives on barriers and supports for outdoor learning in public elementary schools. Methods: Thirty-six teachers in (urban and rural) British Columbia, Alberta, and Ontario (all female; "Mean age" = 43.84, SD = 10) participated in one of five virtually administered, semi-structured focus groups. Questions/prompts facilitated a discussion on teachers' experiences with barriers and supports for outdoor learning. Thematic analysis was used to identify main themes. Results: Four interrelated themes and further sub-themes were found: (1) "Teacher characteristics": interest/motivation to teach outdoors, preparedness, confidence in handling risks; (2) "Systemic factors": principal support, school/district policies, funding/resources, curriculum, school schedule; (3) "Culture": school culture, societal beliefs about education, family backgrounds; (4) "Environmental factors": weather, built/natural environment, hazards. Discussion: Systemic support is needed to integrate outdoor learning in schools. Translation to Health Education Practice: The findings in this study are relevant to health education specialists particularly focused on elementary school education.