Pandemic public health measures have affected mental health for many people, resulting in varied approaches to mental health self-care. During 27 April - 26 July 2020, we surveyed a cohort of 1646 Australians, who were in paid employment prior to the pandemic, on changes in work, health, and managing their mental health concerns. Lifestyle changes were most the most frequently reported action to manage mental health concerns (78%), and were more common for women (OR=2.33, 95%CI=[1.82, 3.03]), and people experiencing recent work loss (OR=1.54, 95%CI=[1.04, 2.28]). Mental health self-care was more common for people experiencing psychological distress, or with pre-exisiting mental health conditions. Talking to friends about mental health, exercise and dietary changes, were more common for women and younger adults. Findings highlight potential benefits of reducing barriers to formal mental health services and supports during crises, particularly for people who less commonly seek help, and those experiencing psychological distress.