Soja jam'i na Sojoji ko Sojawa sune masu yaƙi a ƙarƙashin wata ƙasa ko shugaba . Asalin kalmar Soja tazo ne daga kalmar Turanci ta Soldier. Bisa ga yanayin furucin ne kuma sai Hausawa suke furtawa da soja. Sannan a Turanci ma an aro tane daga tsohuwar kalmar Farasanci ta soudeer ko soudeour, hakanan kalmar ma tana kama da kalmar Medieval ta soldarius, ma'ana "Soja".