Background: Health programs delivered through digital devices such as mobile phones (mobile health [mHealth]) have become an increasingly important component of the health care tool kit. Aboriginal and Torres Strait Islander women of reproductive age are likely to be caring for children and family members and needing health care, but little is known about their access to and interest in mHealth. Objective: The objectives of this study were to investigate Aboriginal and Torres Strait Islander women’s ownership of digital devices, access to the internet, current mHealth use, and interest and preferences for future mHealth. We examined the factors (age, remoteness, caring for a child younger than 5 years, and level of education) associated with the ownership of digital devices, use of internet, and interest in using a mobile phone to improve health. This study also examines if women are more likely to use mHealth for topics that they are less confident to talk about face-to-face with a health professional. Methods: A national web-based cross-sectional survey targeting Aboriginal and Torres Strait Islander women of reproductive age (16-49 years) was performed. Descriptive statistics were reported, and logistic regressions were used to examine the associations. Results: In total, 379 women completed the survey; 89.2% (338/379) owned a smartphone, 53.5% (203/379) a laptop or home computer, 35.6% (135/379) a tablet, and 93.1% (353/379) had access to the internet at home. Most women used social media (337/379, 88.9%) or the internet (285/379, 75.2%) everyday. The most common modality used on the mobile phone for health was Google (232/379, 61.2%), followed by social media (195/379, 51.5%). The most preferred modality for future programs was SMS text messaging (211/379, 55.7%) and social media (195/379, 51.4%). The most preferred topics for future mHealth programs were healthy eating (210/379, 55.4%) and cultural engagement (205/379, 54.1%). Women who were younger had greater odds of owning a smartphone, and women with tertiary education were more likely to own a tablet or laptop. Older age was associated with interest to use telehealth, and higher educational attainment was associated with interest for videoconferencing. Most women (269/379, 70.9%) used an Aboriginal medical service and overall reported high rates of confidence to discuss health topics with a health professional. Overall, women showed a similar likelihood of selecting a topic in mHealth whether they were or were not confident to talk to a health professional about that. Conclusions: Our study found that Aboriginal and Torres Strait Islander women were avid users of the internet and had strong interest in mHealth. Future mHealth programs for these women should consider utilizing SMS text messaging and social media modalities and including content on nutrition and culture. A noteworthy limitation of this study was that participant recruitment was web-based (due to COVID-19 restrictions).