Fido
Fido refers to:

Dogs
Fido (dog), a famous dog and symbol of loyalty
Fido (Lincoln dog), favorite dog of Abraham Lincoln

Art, entertainment, and media
Fictional characters
Fido Dido, a cartoon character associated with the soft drink 7 Up
Fidough, a Pokémon species

Film
Fido (film), a Canadian comedy about a zombie named "Fido"

Music
Fido (band), a punk/rock band from Melbourne, Australia
Fido, one half of Alexis & Fido, a reggaeton duo

Visual art
Fairfield Industrial Dog Object, or Fido, a sculpture in Fairfield, Victoria, Australia

People
Beata Fido (born 1967), Polish actress

Internet and communication
FIDO Alliance, an industry consortium working on internet authentication mechanisms, including the U2F protocol for two-factor authentication.
Fido Solutions, a Canadian cellular, home phone and Internet provider
FidoNet, a worldwide bulletin board system computer network, related to the FIDO bulletin board software package.
A microcontroller version of the Freescale ColdFire (part of the Motorola 68000 series)
.fido a type of Cineon Graphics Data file format.

Military and space
Fido Explosives Detector, a portable explosives detector
Fire Direction Officer or FDO, the third ranking officer in a US artillery battery
Flight Dynamics Officer, a position in ground control of space missions
Fog Investigation and Dispersal Operation, a fog dispersal system developed in the Second World War
Mark 24 Mine or FIDO, a U.S. acoustic homing torpedo used during World War II
Roger Grosjean, an MI5 double agent (codename Fido) in World War II

See also
All pages with titles beginning with Fido
All pages with titles containing Fido