Johanna Meijer (born 26 March 1959) is a Dutch scientist who has contributed significantly to the field of chronobiology. Meijer has made notable contributions to the understanding of the neural and molecular mechanisms of circadian pacemakers. She is known for her extensive studies of photic and non-photic effects on the mammalian circadian clocks. Notably, Meijer is the 2016 recipient of the Aschoff and Honma Prize, one of the most prestigious international prizes in the circadian research field. In addition to still unraveling neuronal mechanisms of circadian clocks and their applications to health, Meijer's lab now studies the effects of modern lifestyles on our circadian rhythm and bodily functions.