With 20 percent of the Mountain State's precincts counted, CNN projected Romney the winner with 71 percent (6,982 votes). Former U.S. Rick Santorum of Pennsylvania, who has dropped out of the race, had 12 percent (2,798) and U.S. Rep. Ron Paul of Texas, the only GOP rival still campaigning, had 10 percent (2,517), CNN said.
There were 31 delegates up for grabs in West Virginia.
Romney won in Indiana (46 delegates) and North Carolina (55 delegates) Tuesday. RealClearPolitics.com said he went into the day's primaries with 865 delegates to 93 for the libertarian-leaning Paul.
Romney needs 1,144 delegates to officially secure the party's nomination to face Democratic incumbent President Barack Obama in the general election in November.
Notable deaths of 2014 [PHOTOS]