They were discovered in a hold-all dumped in Hull Road, off Central Drive, by officers called to the street on a separate matter, police said.
Det Con Daniel Cassidy, from Blackpool CID, believes they may have been stolen from a market stall holder or second hand shop.
Some of the watches – there were more than 150 of them – show signs of wear, and had handwritten price tags on them.
They were loose in the bag and not boxed, he added. Brands include Gucci, Armani, Accurist, Dunlop, Buccino, Citizen, and Pulsar.
Now, more than two weeks after their discovery on Monday, July 25, police have appealed for help in tracing their rightful owner.
Det Con Cassidy said: “We want to re-unite the items with the original owner of the watches, and are asking for anyone with information to contact us.”
Anyone with information can call police on 101, quoting crime reference number WD1604633.