In the digital era, the use of technological tools and platforms has become increasingly prevalent among people, including older adults, for various daily activities such as social interactions, online payments or shopping, entertainment, and information seeking. The prudent use of technology by older adults provides several benefits, allowing them to undertake useful or convenient activities easily. Moreover, older adults with functional and up-to-date technological skills have better employment prospects, enabling them to remain financially independent, economically active, and contribute to the national economy. This study investigates whether demographic factors and internet-related behaviour influence online activities among older adults in Thailand. Data were collected through an online survey, and discriminant analysis was utilised to evaluate the hypothesis. The study’s findings suggest that gender, education, career, income, time spent online, online media platforms, and preferred online content can predict older citizens’ online activities but not marital status. Therefore, to ensure older Thai citizens remain active, well-informed, and connected, this study recommends increasing education, improving the appeal and reliability of digital news and information, and providing income support for older adults.