Raven’s Advanced Progressive Matrices (APM) is a leading global non-verbal mental ability test for identification of individuals with clear thinking skills who can handle rigorous study programmes and cope with complexity and ambiguity of the contemporary workplace. The test is popularly used in America, Europe and Asia but has never been validated for use in Nigeria. A validation sample of 2100 in Nigeria was randomly drawn for this study. Triangulation research design, adopting Item Response Theory (IRT), guided this validation of APM. Results revealed that all items of the test yield favourable statistics under 3-Parameter Logistic IRT Model with regards to discrimination, difficulty and guessing. Item Response Function showed preponderance of APM’s reliability (0.948) and construct cum concurrent validity (0.701) with Culture Fair Intelligence Test (CFIT). X-Calibre analysis confirmed suitable difficulty indexes (-2.595 to 2.133 b parameter) of APM. The APM is bias-free and very suitable for use in Nigeria.