Weight status, weight stigma, and internet use are important factors impacting quality of life (QoL). However, little is known regarding how these factors interact in their association with QoL, and it is important to understand how self-perceived obesity and body mass index (BMI)-defined obesity may differentially impact QoL. We aimed to assess the associations between weight status (obesity vs. non-obesity, including both self-perceived and BMI-defined), weight stigma, internet use, and QoL. Cross-sectional data from the Taiwan Social Change Survey (N = 1604; mean age = 49.22; 52.93 % women) were used. All participants were classified as having obesity or not having obesity according to both self-perceived (self-perceived as 'too fat') and BMI-defined (≧27 kg/m2 as obesity) weight status. Results showed that the group with obesity (both BMI-defined and self-perceived) had significantly more internet time and lower physical QoL than the group without obesity. Those with self-perceived obesity, but not those with BMI-defined obesity, sought health information via the internet and used social media significantly more than the group without obesity. More internet time was associated with worse physical and mental QoL for the group with obesity regardless of BMI-defined or self-perceived status. Moreover, weight stigma was associated with worse mental QoL for the group with self-perceived obesity, but not for the group with BMI-defined obesity. Accordingly, being a person with obesity (self-defined, or based upon BMI) was associated with more internet time and poorer QoL. People with self-perceived obesity may have increased experience of weight stigma and greater internet use, factors that may contribute to their impaired QoL.