Serological methods such as the enzyme-linked immunosorbent assay (ELISA) and virus neutralization test are fundamental tools used in diagnosis, seroepidemiological studies of filovirus transmission/prevalence, and the evaluation of vaccine immunogenicity and potential therapeutic antibodies. Filoviruses have a single transmembrane glycoprotein (GP), which is the only known target of neutralizing antibodies. Here we describe serological methods to quantify filovirus GP-specific antibodies.