There has been a significant increase in the prevalence and estimates of neurodevelopmental disorders, especially autism spectrum disorders, in the last decade. The literature has seen increasing research on understanding wellbeing and mental health. To understand the association and interaction of well-being and mental health with autism and ADHD, a survey was given to 560 secondary school students. The survey used the wellbeing process questionnaire, the autism spectrum quotient, the ADHD self-report scale, and the strengths and difficulties questionnaire. The analysis conducted using SPSS showed that there was a significant correlation between anxiety, depression, AQ, and ADHD. Anxiety and depression were also significantly correlated with all well-being and SDQ variables. The regression analysis showed that anxiety was significantly associated with positive well-being, negative well-being, emotional problems, and prosocial behaviour. In contrast, depression was significantly associated with positive well-being, negative well-being, physical health, flourishing, conduct problems, emotional problems and peer problems. The associations between anxiety, depression and the outcomes were stronger than with either AQ or ADHD