Trencher is a hydraulically powered excavator attachment used to cut consistent trenches for utilities, drainage, irrigation and similar underground installations. Depending on the specific design, trenching is performed by a dedicated cutting system that removes material along a controlled path.

Trenchers are particularly useful where repeatable width and depth are important. Selection must consider ground type, required trench dimensions, carrier hydraulic capacity, excavator size, cutting system configuration and mounting interface. Final operating requirements vary by model.