The present invention discloses fusion proteins comprising transferrin, lactoferrin or melanotransferrin fused to glucagon-like peptide 1 (GLP-1). In one embodiment of the invention, the fusion protein displays increased serum half-life as compared to a GLP-1 peptide in an unfused state. The invention includes a pharmaceutical composition comprising the GLP-1 fusion protein of the invention and a carrier. The fusion protein of the invention can be administered to a subject for treatment of diseases or conditions treatable by GLP-1, including, but not limited to, diabetes, obesity, congestive heart failure and inflammatory bowel syndrome.