买卖圣职（Simony），又称贩卖圣事，是指用金钱买卖教会职位的罪行。Simony来自魔术师西门(Simon)，据《使徒行传8：18-24》记载，西门企图向圣伯多禄购买恩赐圣灵的权力，被圣伯多禄拒绝。

中世纪时，世俗的权力斗争介入教会，皇帝任命受过高深教育的教士为高级官员，世俗权力加速神职人员的腐化。买卖圣职动摇教会的道德水平，情势每况愈下。教会内的改革派呼吁恢复传统的修道生活。克吕尼改革中，教宗额我略七世打击买卖圣职，引起与亨利四世的叙任权斗争。16世纪又暴发宗教改革，马丁·路德大力评击教会买卖圣职、卖赎罪券等，引发教会改革。自此，买卖圣职不复多见。

Simony (/ˈsaɪ.mə.ni/ or /ˈsɪ.mə.ni/) is the act of selling church offices and roles. The practice is named after Simon Magus, who is described in the Acts of the Apostles 8:9–24 as having offered two disciples of Jesus, Peter and John, payment in exchange for their empowering him to impart the power of the Holy Spirit to anyone on whom he would place his hands. The term also extends to other forms of trafficking for money in "spiritual things". Simony was also one of the important issues during the Investiture Controversy.