Barley is a cereal grain cultivated widely across the world. Barley’s wide adaptability is the reason for it being preferred in dry farming systems in several nations. The ever-increasing world population and decreasing agricultural land have led to a serious issue of lower yield per unit area. In this context, the present study aimed to determine the effects of 150 mT of magnetic field (MF) treatment applied at different time points (Control, 24 h, 48 h, and 72 h) on the biochemical characteristics, yield, and yield components of barley plants. Three barley cultivars, namely, Aydanhanım, Bolayır, and Baronesse, were cultivated at Konya and Kayseri locations during the 2020/2021 growing season. An average increase of 24% in the seed yield, 20% in the protein yield, 30% in starch yield, and 35.89% in oil yield were observed in groups that received magnetic field treatments at 48 h and 72 h. at both locations, compared to the control groups, MF treatments led to significant increases in the spike length, number of grains per spike, and 1000 grain weight, all of which are important agricultural traits affecting plant yield. These findings contributed to the information on plant development and biochemical contents after magnetic field application and would, therefore, serve as a reference for future studies on the subject.