A meta-analysis on the validity of tests of general mental ability (GMA) and specific cognitive abilities for predicting job performance and training success in the UK was conducted. An extensive literature search resulted in a database of 283 independent samples with job performance as the criterion (N=13,262), and 223 with training success as the criterion (N=75,311). Primary studies were also coded by occupational group, resulting in seven main groups (clerical, engineer, professional, driver, operator, manager, and sales), and by type of specific ability test (verbal, numerical, perceptual, and spatial). Results indicate that GMA and specific ability tests are valid predictors of both job performance and training success, with operational validities in the magnitude of .5–.6. Minor differences between these UK findings and previous US meta-analyses are reported. As expected, operational validities were moderated by occupational group, with occupational families possessing greater job complexity demonstrating higher operational validities between cognitive tests and job performance and training success. Implications for the practical use of tests of GMA and specific cognitive abilities in the context of UK selection practices are discussed in conclusion.