The lemon plant (Citrus limon L.) is a species from the Rutaceae family that spread from Southeast Asia and spread to all countries in the world. Lemon has been used traditionally since ancient times to treat various diseases and has been tested for various pharmacological activities. The literature review was carried out to study the phytochemical compounds and pharmacological activities of lemon plants. The literature compiled by a minimum of 50 scientific articles using search engines such as Science Direct, Pubmed, and Google Scholar, published for a maximum of the last 10 years, includes a minimum of 20 articles in the last 2 years, has a DOI, and the quality of the journal index is reviewed using Scimago. Lemon is very rich in phytochemical compounds, including flavanones such as hesperidin, eriocytrin, naringin, narirutin, didymin; flavones such as apigenin, luteolin, and diosmin; flavonols such as routine, quercetin, mirisetin, isositrol, limositrol, and limositrin; terpenoids such as limonene, limonoids, and carotenoids. Various kinds of in vivo and in vitro studies provide results of various pharmacological activities such as antioxidants, anticancer, neuroprotective, antimicrobial, antidiabetic, anti-inflammatory, antihyperlipidemic, antiurolithiasis, and antiplasmodial. It is necessary to develop further research on the pharmacological activity of lemon plants in the future.