Background:Unemployment is known to have negative effects on mental and physical health. Yet, the effectiveness of interventions aimed at improving the health of unemployed people is unclear.Methods:We conducted a random-effects meta-analysis of extant intervention studies with at least two measurement points and a control group. A literature search in PubMed, Scopus, and PsycINFO in December 2021 identified 34 eligible primary studies with 36 independent samples.Results:For mental health, the average meta-analytic effect sizes for the comparison of the intervention group and the control group were significant and of small size after the intervention,d= 0.22; 95% CI [0.08, 0.36], as well as at follow-up,d= 0.11; 95% CI [0.07, 0.16]. Effects on self-assessed physical health status were small and marginally significant (p= 0.10) after the intervention:d= 0.09; 95% CI [−0.02, 0.20], and insignificant at follow-up. However, when job search training was not part of the intervention program (i.e., all available resources were used solely for health promotion), the average effect size for physical health was significant after the intervention,d= 0.17; 95% CI [0.07, 0.27]. Furthermore, the effects of physical activity promotion were significant and of small-to-medium size after the intervention, leading to increased levels of activity,d= 0.30; 95% CI [0.13, 0.47].Conclusions:Population-based health promotion programs are recommended because even measures with small effect sizes can actually improve the health of a large group of unemployed people.