Internet　addiction　(IA)　is　prevalent　and　associated　with　negative　measures　of　health　functioning,　with　males　appearing　more　vulnerable　than　females.　However,　little　is　known　about　gender-related　differences　in　the　effect　sizes　of　IA　globally.　This　multinational　meta-analysis　addresses　this　gap　in　knowledge　by　providing　estimates　of　effect　sizes　of　gender-related　differences　in　IA　tendencies　across　jurisdictions　and　how　they　relate　to　global　national　indexes　including　gross　domestic　product　(GDP)　per　capita,　internet　penetration,　gender-related　gaps　in　economies,　internet　penetration,　alcohol　consumption,　smoking　prevalence,　life　satisfaction　and　suicide　rates.　One-hundred-and-one　studies　consisting　of　115　independent　samples　involving　204,352　participants　from　34　countries/regions　were　identified.　The　average　effect　size　of　gender-related　differences　in　IA　in　a　random-effects　model　was　small　at　g　=　0.145.　The　highest　gender-related　effect　sizes　were　in　Asia　with　g　=　0.208,　and　the　lowest　were　in　the　North　America　with　g　=　−0.049,　Africa　with　g　=　0.092　and　Europe　with　g　=　0.114.　Meta-regression　revealed　that　smaller　effect　sizes　were　observed　in　nations　with　greater　GDP　per　capita　and　higher　internet　penetration.　As　operationalized,　both　the　internet　availability　and　social　norms　hypotheses　were　supported　by　effect　sizes　being　positively　related　to　gender-related　differences　in　economic　measures,　internet　penetration,　smoking　prevalence　and　alcohol　consumption.　The　Psychological　Well-being　hypothesis　was　largely　not　supported,　since　the　effect　sizes　were　unrelated　to　gender-related　differences　in　life　satisfaction　and　negatively　related　to　gender-related　differences　in　suicide　rates.　Findings　suggest　economic　factors,　internet　availability,　social　norms　and　some　addiction-related　health　factors　may　relate　importantly　to　gender-related　differences　in　IA　tendencies　across　countries.　©　2019　The　Authors