Emergency services attended and the person was pronounced dead at the scene.
Motorists faced delays of more than an hour following the crash.
The M8 was closed eastbound at junction 4A for a time and Traffic Scotland tweeted that at around 7am travel time from J5 to J4 was approximately one hour and 20 minutes.
The road had reopened by 7.55am but motorists still faced delays of more than an hour.
A Police Scotland spokeswoman said: “At around 12.20am on Friday June 18 2021, police were called to a report of a person having been struck by a vehicle on the M8 eastbound near Whitburn.
“Emergency services attended and the person was pronounced dead at the scene.”
Police Scotland said that investigations into the crash are continuing.