Calcium (Ca2+) and reactive oxygen species (ROS) are key secondary messengers in plant stress signaling, yet their interplay in regulating proteome-wide responses remains poorly understood. We employed label-free quantitative (LFQ) proteomics to investigate Ca2+-dependent and independent proteome changes in Arabidopsis thaliana leaves upon oxidative stress induced by hydrogen peroxide (H2O2). To dissect the role of Ca2+ signaling, we inhibited H2O2-induced Ca2+ transients by pretreatment with LaCl3, a plasma membrane Ca2+ channel blocker. Throughoutall four treatment samples – control, H2O2 treated, LaCl3 treated, H2O2 and LaCl3 treated, we identified a total of 3724 and 3757 proteins after 10 and 30 min, respectively.