Abiotic stress factors such as drought, heat, and soil salinity pose serious challenges to plant growth, especially in the face of increasing climate change. In Europe, major droughts and heatwaves have had a negative impact on agriculture, viticulture, and forestry. In addition, multiple stress factors—such as nutrient deficiencies, flooding, frost, and pollution—are also contributing to declining crop yields and threatening global food security. While breeding has traditionally focused on resistance to biotic stress and yield, abiotic stress tolerance has become increasingly important, with genetic studies identifying the most important traits. Proteomics evolved as a valuable tool in stress research, providing physiological insights into plant adaptation through changes in protein composition. Despite its potential, proteomics still faces challenges such as high costs and data complexity, but advances in omics technologies will further improve understanding of tolerance mechanisms and support breeding efforts for resilient plants. The chapter highlights previous results of proteomic studies from the last decade to identify major leaf proteins involved in drought tolerance and adaptation, as well as linkage to heat and salt stress responses.