Public health measures to reduce COVID-19 transmission include masking in public places, physical distancing, staying home when ill, avoiding high-risk locations, using a contact tracing app, and being willing to take a COVID-19 vaccine. However, adoption of these measures varies greatly. We aimed to improve health messaging to increase adherence to public health behaviours to reduce COVID-19 transmission by: 1) determining attitudes towards public health measures and current behaviours; 2) identifying barriers to following public health measures; and, 3) identifying public health communication strategies. We recruited participants from a random panel of 3000 phone numbers across Alberta to fill a predetermined quota: age (18-29; 30-59; 60+ years), geographic location (urban; rural), and whether they had school-age children. Two researchers coded and themed all transcripts. We performed content analysis and in-depth thematic analysis. Nine focus groups were conducted with 2-8 participants/group in August-September, 2020. Several themes were identified: 1) importance of public health measures; 2) compliance with public health measures; 3) critiques of public health messaging; and 4) suggestions for improving public health messaging. Physical distancing and masking were seen as more important than using a contact tracing app. There were mixed views around willingness to take COVID-19 vaccine. Current public health messaging was perceived as conflicting. Participants felt that consistent messaging and using social media to reach younger people would be helpful. In conclusion, these findings provide insights that can be used to inform targeted (e.g., by age, current behaviour) public health communications to encourage behaviors that reduce COVID-19 transmission.