[Edit]

Science and technology

Echo (phenomenon), a natural acoustic phenomenon named after the nymph.

Light echo, a visual phenomenon seen when light from a rapidly brightening object such as a nova is reflected from interstellar matter.

Echovirus, short for "enteric cytopathic human orphan" virus.

Echo I or Echo II, classes of Soviet submarines.

Echo satellite, one of the first communications satellites.

Echo sounding, a way to measure water depth.

Forward echo, a type of reflection on a transmission line.

Reverse echo, a variation on forward echo.

Echo cancellation, techniques for reductions in the perception of electrical and acoustic echo.

Radiofrequency signals from spins generated after a time delay by some mechanisms in NMR & MRI, e.g. spin echoes and gradient echoes.

Computers

Echo (computing), a Unix command to display a line of text.

ECHO protocol, an internet protocol.

Echo (framework), a web framework for Java programming.

Echo (fidonet), a discussion forum on FidoNet, similar to a Usenet Newsgroup.

/echo, a command in mIRC's scripting language.

Echo (Echonyc.com) an online community, "the East Coast answer to the WELL."

Fiction and mythology

Echo (mythology), a nymph from Greek mythology.

Echo (comics), a character in the Marvel universe.

The Echoes, aliens from the UK TV series Invasion Earth.

Echo Base, the base of operation for the Rebel Alliance in the Star Wars Universe.

Echo Point, a Austrailan soap opera.

Music

Echo (band), a jazz/electro band from New York City.

Echo (song), a song by the nu metal group Trapt.

Echo (album), any of several albums by this name.

Echo (record label), a recording label.

ECHO, a German music award.

Echo & the Bunnymen, a rock band.

The Echo (venue), a venue in Los Angeles, California.

Miscellaneous

ECHO (European Commission), the humanitarian aid department of the EU.

A letter in the NATO phonetic alphabet.

Toyota Echo, a model of automobile sold in North America.

Fox's Echo, a chocolate bar.

Echo magazine, The Quarterly Echo Student Magazine.

60 Echo, an asteroid.

The echo poem Surrealist technique.

English-language newspapers:

The Echo (Irish Newspaper) a regional newspaper in Dublin, Ireland.

The Northern Rivers Echo

The Northern Echo

The Irish Echo

The Liverpool Echo

The Evening Echo

The Northampton Chronicle and Echo

The Haliburton Echo

Echo Weekly an alternative newspaper in Kitchener, Ontario.

Places

Echo, Minnesota

Echo, Oregon

Echo Township, Minnesota

Echo Township, Michigan

Echo Lake, Washington