EQcorrscan is an open‐source Python package for the detection and analysis of repeating and near‐repeating seismicity. The package provides reliable, well‐tested, system‐agnostic implementations of matched‐filter and subspace detection. Detection can be carried out on machines of diverse architectures, ranging from single‐board computers, workstations, and servers to supercomputers and distributed computing environments. The package has been developed in Python to provide readable and user‐friendly code and is accompanied by comprehensive and continuously updated documentation and examples. Because the package is written in Python, and extensively leverages ObsPy, EQcorrscan can be run on all major operating systems and can parse most commonly used seismological data formats. In addition to the core detection routines, EQcorrscan includes functions for template creation, stacking (both linear and phase‐weighted stacking), magnitude calculation (including singular value decomposition‐derived relative moments), event clustering, and others. Numerically intensive routines are written in C to improve efficiency.