The angiotensin II receptor type 1 (AGTR1), a G protein-coupled receptor (GPCR), plays a critical role in the renin-angiotensin system (RAS), primarily mediating the effects of angiotensin II (Ang II), a key peptide hormone regulating blood pressure, fluid balance, and cardiovascular homeostasis. AGTR1 activation triggers vasoconstriction, aldosterone release, sodium retention, and cellular proliferation, contributing to hypertension, cardiac remodeling, and renal dysfunction. Dysregulation of AGTR1 signaling is implicated in pathologies like heart failure, atherosclerosis, and diabetic nephropathy. AGTR1-specific antibodies are tools used to study receptor expression, localization, and function in research settings. These antibodies, often monoclonal or polyclonal, enable techniques such as Western blotting, immunohistochemistry, and flow cytometry. Therapeutically, AGTR1 antagonists (ARBs, e.g., losartan, valsartan) are widely prescribed for hypertension and cardiovascular diseases, though AGTR1-targeting antibodies themselves are less common in clinical use. Recent studies explore AGTR1 antibodies in diagnostic applications or as potential biologic drugs to modulate receptor activity with higher specificity. Their development faces challenges, including ensuring target selectivity and minimizing off-target effects. Overall, AGTR1 antibodies remain vital for elucidating RAS mechanisms and advancing therapeutic strategies against AGTR1-associated diseases.