The United Kingdom (UK) is becoming increasingly diverse (Office for National Statistics, 2013). Educational psychologists in the UK will need to feel competent in providing services to an increasingly multicultural population. This research study used a mixed method, two-phase, sequential, explanatory study design to explore the self-perceived intercultural competence of UK educational psychologists and trainee educational psychologists (EP/Ts). The study also explored EP/Ts experiences of working with culturally diverse populations. The first phase of this research study used an online adapted version of the MCCTS-R (Holcomb-McCoy & Myers, 1999; Munoz, 2009), and the second phase built upon the first phase with follow-up semi-structured interviews, analysed using Braun & Clarke's (2006) thematic analysis. The results of this research study present a breadth and depth of information. EP/Ts generally perceived themselves to be competent to work cross-culturally with particular areas of competence including knowledge of assessment bias, poverty effects, and positive attitudes towards diverse cultures. EP/Ts also reported areas of lower competence including theories of racial/ethnic identity development, limited experiences of community work and limited knowledge of community resources. However, EP/Ts perceptions about development needs depended upon their awareness. The process of participating in the study raised awareness of gaps in knowledge and limitations in practice. The study concludes with a discussion of implications for the practice of EP/Ts.