Inadequate water, sanitation, and hygiene (WASH) among urban poor women is a major urban policy concern in low- and middle-income countries (LMICs). There was a paucity of systematic information on WASH among the urban poor during the pandemic. We reviewed the opportunities and challenges faced by the urban poor in LMICs during the COVID-19 pandemic. We used the PRISMA guidelines to conduct a comprehensive search of 11 databases, including MEDLINE, Embase, Web of Science, and CINAHL, between November 2019 and August 2021. We used thematic analysis to synthesize the qualitative data and meta-analyses to estimate the pooled prevalence. We screened 5008 records, conducted a full-text review of 153 studies, and included 38 studies. The pooled prevalence of shared water points was 0.71 (95% CI 0.37-0.97), non-adherence to hygiene practices was 0.15 (95% CI 0.08-0.24), non-adherence to face masks was 0.27 (95% CI 0.0-0.81), and access to shared community toilets was 0.59 (95% CI 0.11-1.00). Insufficient facilities caused crowding and long waiting times at shared facilities, making physical distancing challenging. Women reported difficulty in maintaining privacy for sanitation, as men were present due to the stay-at-home rule. Due to unaffordability, women reported using cloth instead of sanitary pads and scarves instead of masks.