Since the handover of the sovereignty of Hong Kong from Britain to China in 1997, convergence between Mainland China and Hong Kong has gradually emerged. During this process, young people have engaged in demonstrations to express their dissatisfaction with government policies and limited socio-economic progression. However, the underlying reasons for their dissatisfaction have not been fully investigated. This study investigates their perceived challenges and opportunities during the convergence, with the objective of identifying the factors affecting the Mainland China–Hong Kong convergence and examining young people’s perceived challenges and opportunities during the convergence. Mixed research methods of focus groups and a survey were adopted. Ten focus groups with 83 participants were conducted to collect qualitative data on the factors relating to convergence. Based on the qualitative data, a questionnaire was constructed to investigate young people’s perceived challenges and opportunities during the convergence, using a sample of 1253 young people. Ordinary least-squares regression was applied to analyse the relationships among identified factors. The study found that Hong Kong’s youth tended to regard the Mainland China–Hong Kong convergence as an opportunity for socio-economic progression, and they identified three challenges during the convergence. It also revealed that young people’s higher education, perceived housing challenges, and perceived socio-economic challenges are negatively related to the convergence, whereas their perceived challenges associated with entrepreneurship and innovation are positively related to the convergence. The development of more well-balanced and mutually beneficial policies that satisfy the needs of young people will lead to a higher acceptance of the convergence. As such, young people will be more willing to embrace the opportunities and face the challenges brought about by the convergence, resulting in a more harmonious society and socio-economic progression.