Major damage was caused to the inside of the Castle, on New Road, in the early hours of Saturday.
The pub has been closed this month but was undergoing a refurbishment in readiness for new owners.
Area manager Ali Martinez said she was devastated by the blaze and that it was not yet known when the pub would reopen. She said extensive damaged had been caused inside.
A severe fire at the Castle pub in Willenhall has caused major damage inside the building pic.twitter.com/2xfS1pH6c6
— Richard Guttridge (@RichG_star) November 17, 2018
The pub had been due to re-open in the coming weeks under new management. Cause of the fire is not yet known pic.twitter.com/dXLmzf5rLl
— Richard Guttridge (@RichG_star) November 17, 2018
West Midlands Fire Service tweeted:
We still have two fire engines and 10 firefighters at The Castle pub in Willenhall. Four crews responded to a severe fire in the building at 4.40am. The fire is now out and our investigators are at the scene to establish how it started. pic.twitter.com/sk5EUoGaQc
— West Midlands Fire Service (@WestMidsFire) November 17, 2018
Investigations into the cause of the blaze at the pub, on the main road into Willenhall, were continuing over the weekend and firefighters remained on site on Saturday afternoon.
The exterior of the building had been spruced up prior to the fire.
Ms Martinez said: "We're devastated because it's a great pub and we have put a lot of money in. We're hoping to get back up and running as soon as possible."
Crews from Fallings Park, Bilston and Walsall tackled the blaze, which started at 4.40am.
West Midlands Fire Service said on Saturday morning: "We still have two fire engines and 10 firefighters at the Castle pub in Willenhall. Four crews responded to a severe fire in the building at 4.40am. The fire is now out and our investigators are at the scene to establish how it started."
