Various embodiments of abrasive jet cutting systems are disclosed herein. In one embodiment, an abrasive jet system includes a cutting head configured to receive abrasives and pressurized fluid to form an abrasive jet. The system also includes an abrasive source configured to store abrasives that are supplied to the cutting head, as well as a fluid source configured to store fluid that is supplied to the cutting head. The system further includes a gas source configured to store pressurized gas that is selectively supplied to the cutting head. When supplied to the cutting head, the pressurized gas can advantageously affect, such as by at least partially diffusing, the abrasive jet.