<p>Imagining performing a movement without executing it (movement imagery) is a covert and multidimensional skill. Leading models propose that the sub-processes of imagery generation, maintenance and manipulation are critical to movement imagery. However, measuring these individual processes, and the potential relationships between them, remains challenging. Here we developed and validated a combination of online tests to assess these different processes. A total of 180 healthy individuals completed the Movement Imagery Questionnaire–Revised, Second Edition (MIQ-RS; generation), the Imagined Finger Sequence Task (iFST; maintenance) and the Hand Laterality Judgement Task (HLJT; manipulation). MIQ-RS showed a bifactorial structure (visual and kinaesthetic modalities) according to confirmatory factor analysis, with good internal consistency. In the iFST, internal validity analyses showed a clear effect of sequence complexity, in both execution and imagery. Reliability, estimated via signal-to-noise ratios (SNRs), was also adequate (SNR ≥ 1.6). In the HLJT, expected effects of rotation angle, hand view and their interaction were found, consistent with biomechanical constraints. Reliability was also adequate (SNR ≥ 1.75). Test–retest reliability (123 participants reassessed after 6–8&#xa0;days) was generally adequate (intraclass correlation coefficients (<i>ICC</i>s) ≥ 0.67). Notably, criterion validity across tests, assessed using Bayesian Spearman’s correlations, showed that correlations were generally absent (<i>BF</i>₀₁ ≥ 3) or of small magnitude (<i>r</i> ≤ 0.27). We conclude that the online versions of these tests showed adequate structural/internal validity and (test–retest) reliability. Importantly, weak criterion validity across tests suggests that the differing sub-processes underlying movement imagery are largely dissociable, underscoring the need for comprehensive, multidimensional assessment of movement imagery ability.</p>