Lloyd Allayre Loar (1886–1943) was an American musician, instrument designer and sound engineer. He is best known for his design work with the Gibson Mandolin-Guitar Mfg. Co. Ltd. in the early 20th century, including the F-5 model mandolin and L-5 guitar. In his later years he worked on electric amplification of stringed instruments, and demonstrated them around the country. One example, played in public in 1938 was an electric viola that used electric coils beneath the bridge, with no back, able to "drown out the loudest trumpet."