We report a mass spectrometry-based proteomics approach to advance the study of the feline proteome. We analyzed immortalized feline cells, various tissues and plasma using data-dependent acquisition (DDA) on a Q Exactive HF mass spectrometer to develop a Felis Catus PeptideAtlas from 157 acquired runs. Data were analyzed using the Trans-Proteomic-Pipeline. We report in the first PeptideAtlas of the domestic cat the identification of 242,844 unique peptides representing 8,972 feline proteins or 45.6% of the predicted UniProtKB Felis catus proteome based on 19,655 unique genes and their representative protein sequences.