Membrane　distillation　(MD)　and　membrane　contactor　(MC)　have　received　a　lot　of　attention　in　ammonia　removal　and　recovery　due　to　the　use　of　hydrophobic　membranes　that　allow　the　volatile　ammonia　gas　to　pass　through.　This　comprehensive　review　summarizes　practical　applications　and　mass　transfer　models　of　ammonia　recovery　from　wastewater　using　MD/MC　technologies.　First,　a　bibliometric　analysis　of　published　literature　was　performed　from　2001　to　2021,　and　the　ammonia　recovery　process　and　various　types　of　membrane　devices　are　becoming　research　hotspots　recently.　Second,　the　most　widely　investigated　influencing　factors　including　feed　and　permeate　characteristics,　membrane　characteristics　and　operating　conditions　on　ammonia　removal　are　critically　reviewed.　The　ammonia　removal　was　greatly　dependent　on　operating　conditions　rather　than　the　feed　and　permeate　solution　characteristics,　while　membrane　and　devices　characteristics　are　of　tremendous　research　interest.　Then,　theo-retical　and　empirical　models　of　ammonia　gas　transfer　in　the　feed,　permeate　and　membrane　are　analyzed　to　predict　the　fate　of　ammonia　gas　in　MC/MD.　Finally,　the　challenges　including　membrane　wetting　and　fouling,　lack　of　long-term　experience,　development　of　accurate　ammonia　transfer　models,　and　nutrient　co-recovery　process,　are　discussed　in　detail,　and　corresponding　research　directions　are　suggested.