Emergency services cleared the area following the discovery on a building site on Ariel Way in White City.
The WWII shell was approximately 13.5 inches in length and around six inches wide.
The London Fire Brigade and Police set-up a cordon and a wider exclusion zone of 400 metres around the site.
London Underground and local rail services were also temporarily suspended.
London Fire Brigade said: “The incident was declared safe and exclusion zones have been lifted.
“The Brigade was called at 1159 and the incident was over at 1243.”