The influence of household crowding on physical and mental health has been well documented. However, research on the influence of household crowding on violent discipline and neglect of children is scarce. Therefore, we aimed to investigate whether household crowding was associated with violent discipline and neglect of children in low- and- middle-income countries (LMICs). Cross-sectional data for 280,005 and 73,030 children in 26 LMICs surveyed using the Multiple Indicator Cluster Survey were analyzed for (1) violent discipline and (2) neglect, respectively. In each country, we used logistic regression models to estimate the effects of household crowding on multiple forms of violent discipline and stimulation activities (as a proxy of the level of child neglect). Estimates were pooled using random effects meta-analyses. After adjusting for confounding variables, household crowding was associated with higher odds of any violent discipline (odds ratio (OR) = 1.09, 95% CI 1.03 to 1.15, p = 0.002) and lower odds of engaging in four or more stimulation activities (OR = 0.88, 95% CI 0.83 to 0.94, p < 0.001). The associations were stronger for urban children and children living in low- and lower-middle-income countries. The findings suggest that screenings and interventions aimed at reducing the effects of household crowding might be effective in preventing and controlling violent discipline and neglect of children in LMICs.