Aim: To synthesize the best available research evidence regarding the effectiveness of spiritual intelligence educational interventions on spiritual intelligence and professional outcomes in nurses and nursing students. Background: Spiritual intelligence is a form of intelligence with which individuals can deal with a crisis, alter situations, solve problems and achieve goals through a set of capacities and abilities. Possessing spiritual intelligence contributes to professional practice and competence in the workplace and has been seen to be beneficial for nurses and nursing students. Nursing interventions to teach and increase understanding of spiritual intelligence have been explored in the literature, but the effectiveness of spiritual intelligence training for nurses and nursing students remains uncertain. Design: A systematic review and meta-analysis. Data sources: A three-step systematized search of sixteen electronic English and Persian databases was conducted to identify randomized and non-randomized trials published in English and Persian from January 2000 to November 2021. Methods: The methodological quality of eligible studies was undertaken by two independent reviewers using the Medical Education Research Study Quality Instrument. Meta-analyses were undertaken where appropriate using STATA v16. Results: Seven studies involving 512 participants were included. Pooled results demonstrated that those who received the educational intervention had significantly higher spiritual intelligence scores at 2 weeks (MD 13.38, 95 % CI: 5.76, 20.99) and one month follow up (MD 20.03, 95% CI: 6.61, 33.45) compared with those who did not. No difference in spiritual intelligence scores was observed among those who received spiritual intelligence education or life skills training (MD 7.52, 95 % CI −1.78, 16.82). Significantly higher communication skills (MD 5.41, 95 % CI: 2.16, 8.66), job satisfaction (MD; 11.30, 95 % CI: 8.63, 13.97) and spiritual care competence (MD; 28.55, 95 % CI: 26.08, 31.02) and decrease in overall stress (MD; 10.30, 95 % CI: 6.84, 13.76) among those who received the educational interventions were reported at the one-month follow-up. Significantly higher job satisfaction levels were also reported at 2-month follow-up among those who received the educational interventions (MD; 16, 95 % CI: 11.06, 20.94). Conclusions: The evidence from this review demonstrates that spiritual intelligence educational interventions have a positive effect on spiritual intelligence and professional outcomes in nurses and nursing students. We noted that the outcomes in the studies included were mostly measured at one-month follow-up and with subjective measures. Longer trials with objective measures are required to provide higher levels of evidence. The results of this review are largely based on single trials and were limited in terms of the number of outcomes. Conducting further trials is warranted to identify the influence of such education on various professional outcomes in nursing practice. Tweetable Abstract: Systematic review and meta-analysis shows spiritual intelligence educational interventions have a positive effect on nurses' and nursing students’ spiritual intelligence, work-related stress and professional practice.