MAX IV Laboratory is a Swedish national synchrotron laboratory that has operated as a user facility since 2016. It is the successor to MAX-lab, which was in operation between 1987 and 2015. MAX IV offers access to several beamlines that provide modern X-ray spectroscopy, scattering/diffraction, and imaging techniques to contribute to solving scientific questions in a wide range of areas. The beamlines are open to academia, research institutes, industry, and government agencies worldwide through the user access programmes.

The X-ray light at MAX IV is produced by an accelerator complex comprising a linear accelerator and two storage rings (1.5 GeV and 3 GeV) for electrons.