Recent research on attitudes towards inclusion uses almost exclusively explicit measures such as questionnaires. Unfortunately, explicit attitude measures are biased by social desirability, particularly when the attitude object is 'sensible', as with inclusive education. Implicit attitude measures are less prone to social desirability, but research on implicit attitudes towards inclusive education is scarce. Thus, we introduce a new attitude measure based on the Single-Target Implicit Association Test (ST-IAT). In our study, 163 teacher students took the new implicit attitude test and completed questionnaires on their explicit attitudes towards inclusive education and persons with disabilities and a comprehensive scale on socially desirable responding. The results support the psychometric quality of our 'Inclusion ST-IAT'. The implicit and explicit attitude measures are correlated but empirically distinct. Furthermore, the social desirability scores were associated with explicit but not with implicit attitudes towards inclusion, i.e. our measure of attitudes towards inclusion (a sensible topic) was not biased by social desirability. We propose that implicit measures should be used to reduce the influence of social desirability in inclusive education research. To encourage replications, we outline important research questions and provide the source code of our ST-IAT, which is open and free to use.