The Critical Disability Theory was developed in the 2000s in response to the critiques of the Social Model of Disability. This study aims to make a theoretical contribution to the Critical Disability Theory as a field of disability studies in the Global South, with Thailand as the target region. The first objective is to use the Critical Disability Theory to understand the social and political aspects of disability, such as oppression and discrimination, through disabled people’s experiences. The second is to show that people with disabilities can be the main agents in changing the society to realise equal rights, using the Critical Disability Theory. This study consists of a literature review and field research. The literature review was conducted in Japan while the field research was conducted in seven provinces of Thailand – Chiang Mai, Ubon Ratchathani, Pathum Thani, Nakhon Pathom, Nonthaburi, Bangkok, and Chonburi – from April 2022 to July 2023. All the interviews for qualitative research were in-depth, with 61 respondents – 33 disabled and 28 non-disabled. The interviews revealed the social constructions of impairment and disability. Furthermore, they showed that people with disabilities accept themselves positively, support each other, and try to change society with their peers. Buddhist meditation is useful for people with disabilities to understand their situation. Disabled people’s organisations are service providers for people with disabilities in the current public health system. People with disabilities expressed their political opinions and identities on social media platforms. In Thailand, people with disabilities alternate between gaining self-confidence and participating in society, thereby improving their capabilities for practical reasons and affiliations. In Thailand, empathy for the experiences and practices of people with disabilities is increasing as Thai society is facing rapid ageing, leading to a growing population of older adults with disabilities. In conclusion, changing the conceptual understanding of the disability of people will promote independent living and reform the discriminatory structure against people with disabilities.