A Fortune 500 corporation, Eli Lilly had revenues of $20 billion in 2008, making it the 148th largest company in the United States and the 10th largest corporation by global pharmaceutical sales. The company is publicly traded on the New York Stock Exchange and is a member of the S&P 500 stock index. Eli Lilly was one of the Nifty Fifty stocks that propelled the mid-20th century bull market.

The company's founder was Colonel Eli Lilly, a pharmaceutical chemist and Union Army veteran of the American Civil War. Col. Lilly served as the company president until his death in 1898. A stylized version of his signature still appears in the company's red logo.  After he mustered out of the Union army, Lilly briefly became a cotton planter in Mississippi, but the venture failed and he returned to the Midwest, where he was a partner in a Paris, Illinois, drugstore. Lilly began formulating plans to create a medical wholesale company while working in partnership at the Binford and Lilly drug store in Illinois.

In addition to internal research and development activities Lilly is also involved in publicly funded research projects with other industrial and academic partners. One example in the area of non-clinical safety assessment is the InnoMed PredTox, a collaboration with pharmaceutical companies, research organizations, and the European Commission to improve the safety of drugs. In 2008 this consortium, which included Lilly S.A. (Switzerland), secured a €8 million budget for a 40-month project that was coordinated by the European Federation of Pharmaceutical Industries and Associations (EFPIA), an organization who represents the research-based pharmaceutical industry and biotech companies operating in Europe. In 2008 Lilly's activities included research projects within the framework of the Innovative Medicines Initiative, a public-private research initiative in Europe that is a joint effort of the EFPIA and the European Commission.

As of July 2014, the company had 8 products at Phase III of development: baricitinib for rheumatoid arthritis, ixekizumab for psoriasis, tabalumab for lupus, evacetrapib for high-risk vascular disease, basal insulin peglispro for diabetes, solazenumab for Alzheimer's, tanezumab for pain, and necitumumab for squamous non small cell lung cancer.