Background Discrimination in intimate relationships (IR) is frequently reported among persons with schizophrenia. Despite ongoing effort of international organizations to combat mental illness stigma, there remain a limited understanding of specific IR-related stereotypes. Aims The study aimed to i) identify the stereotypes related to IR of persons with schizophrenia held by Mental Health Professionals (MHP), health students and the general population, and ii) explore the effects of several factors associated with these stereotypes. Methods This study used a mixed-methods approach. A survey developed collaboratively with persons with lived experience of mental health conditions (PWLE) was disseminated among MHP, health students and the general population. Results The majority of the nine IR-related stereotypes previously identified by PWLE were endorsed by the participants (N = 532). PWLE were perceived as particularly incompetent in the domain of IR (e.g. to achieve couple project). Stereotypes endorsement varied among the groups. Continuum beliefs, perceived similarities and recovery beliefs were negatively associated with stereotype endorsement. Conclusions The general population, MHP and health students endorsed several stereotypes regarding IR of persons with schizophrenia. The results provide support for the role of theoretical beliefs in IR stigmatization, suggesting they may be relevant targets for evidence-based stigma reduction programs.