The number of shares to be sold in the IPO and the price range have not been determined, Britannica said.
Apart from its two iconic publications, the Chicago-based company also offers digital courses and technology for multimedia learning in schools.
The Encyclopaedia Britannica was first published in 1768 in Edinburgh, Scotland and went digital-only more than a decade ago as the internet made its leather-bound reference guides redundant.
Merriam-Webster, first published in the early 19th century, has been one of the most popular reference tools in lexicography.
The company joins a number of firms looking to test investor appetite for new listings, as hopes of a soft landing grow.
Companies sometimes file confidentially for IPOs to keep their financial details private for longer.
(Reporting by Niket Nishant in Bengaluru; Editing by Shweta Agarwal)
