The new device, made by LG, comes after many months of rumours and speculation. It replaces the Nexus 4 which was discontinued some weeks ago.
The Nexus 5 is smaller, slimmer and lighter than its predecessor though its screen is larger coming in at 4.96 inches or 126mm.
It is the first device to feature Google's much talked about Android Kit Kat and specifications for the new phone were widely leaked before it was announced on the official Google blog.
The new phone has record and playback HD video at the full 1080p resolution. Its camera also has a rapid burst system that captures several photographs at the same time allowing for a better chance to grab that special moment! so owners can pick the best shot.
The handset is due to go on sale on 1 November in the US, UK, Canada, Australia, France, Germany, Spain, Italy, Japan and Korea.
In the UK the device is advertised at £299 for the 16Gb model, $349 in the US, or £339 for the 32Gb model, or $399 in the US. The phone is also available in either black or white.
tvnewswatch, London, UK