© 2019 The Australian Psychological Society Objective: Largely as a result of national surveys which have monitored the trends of individuals' well-being from various perspectives, Australia is known to be a country in which people generally experience a high level of quality of life. Beyond the overall trends, this article aims to explore demographic, social, and psychological variables associated with Australians' life satisfaction, and identify important factors in each age and gender group. Method: We analysed the data from the Gallup World Poll, which has collected nationally representative samples from Australia from 2005 to 2017. Results: Overall, the data suggest that the relationship between age and life satisfaction is U-curved. The gender gap remains consistent, favouring women across age groups. Although material quality of life is found to be the prime factor, the study also points to gender- and age-specific factors that influence people's life satisfaction. The relative importance of city/area satisfaction to Australians' sense of well-being is identified. Conclusions: Our comprehensive analysis implies that there is a need for better income support for people with very low incomes to improve their life satisfaction. Also, it would be of great benefit to Australia for the government and relevant policy makers to pay special attention to the improvement of healthcare services for the country's ageing population.