Lactoferrin is a multifunctional protein found in the mammalian milk and is particularly abundant in the colostrum. Large amounts of this protein can be prepared from bovine milk using membrane separation technology. Several studies have reported about the physical and chemical properties, physiological functions, and results of clinical trials related to treatment with bovine lactoferrin. Bovine lactoferrin has also been used as a supplement in several foods as a functional material, which has increased its demand in recent years. This review focuses on the applications of bovine lactoferrin in the health promotion and clinical fields, including treatment with the protein to protect against infection and improve anemia. In addition, we report the findings of our study that include assessments of its potential for inhibiting catechol-O-methyltransferase and the results of a clinical trial that used bovine lactoferrin in an enteral liquid formula to treat bedridden patients.