表皮生长因子（Epidermal growth factor，EGF）是最早发现的生长因子, 对调节细胞生长、 增殖和分化起着重要作用。在人类，表皮生长因子蛋白有53个氨基酸残基，三个二硫键，质量6千道耳顿。

表皮生长因子通过与细胞表面的受体表皮生长因子受体(EGFR)结合而起作用。与表皮生长因子受体的高亲和力结合，激发受体内在的酪氨酸激酶的活性，从而启动了信号传导级联而导致多种生物化学变化，细胞内钙水平上升, 增加糖酵解与蛋白质合成, 增加某些基因(包括表皮生长因子受体)的表达, 最终导致DNA合成和细胞增殖。

Epidermal growth factor (EGF) is a growth factor that stimulates cell growth, proliferation, and differentiation by binding to its receptor EGFR. Human EGF is a 6045-Da protein with 53 amino acid residues and three intramolecular disulfide bonds.

EGF was originally described independently as a secreted peptide found in the submaxillary glands of mice and in human urine. Initially, human EGF was known as urogastrone.