Research evidence linking managing group dynamic (GPD) to the effectiveness of academic and non-academic staff of Nigerian universities, is ostensibly scarce. While existing studies have majorly addressed the performance impact of group dynamics in general perspectives, there is a gap in gauging how managing dynamics in groups could lead to the effectiveness of staff of Nigerian universities. Built on two complementary theories, the study has sought to investigate the relationship between pooled constructs of group dynamics, including social integration (SI), team leadership (TL), interpersonal facilitation (IF), group efficacy (GE); and effectiveness of university staff in those measures as in productivity (PD), adaptability (AD), and flexibility (FL). The sample size of 253 staff was selected from 2050 staff, and a self-structured questionnaire was designed. Instrument reliability was confirmed for the individual construct of GPD and staff effectiveness (SE) and Confirmatory Factor Analysis (CFA) which was used to validate the instruments. The frequency and percentage table, means, and standard deviations were engaged as descriptive tools. Linear and multiple regressions and variance inflation factor were designed to test hypotheses and relationships. Findings revealed a significant statistical relationship between the dimensions of GPD and measures of staff effectiveness except for the dimension of GPD (SI) with a weak aggregate predictive contribution. The study posited the need for management of the federal universities to forge integration with staff through adapting strategies of group dynamics to improve the effectiveness of academic and non-academic staff of universities. Especially, staff with innate creative ability and genius for innovation should be supported and motivated to reach their potential.