Venezia (Venice) to Dubrovnik by ferry

Unfortunately not    :'(

At the present, there are no direct ferries sailing between Dubrovnik and Venice.

However, if you wish, you can do that journey using some ferries and some buses along the Croatian coast.

Starting from Dubrovnik take the ferry to Split and then the bus to Rijeka and Istria.

Update >>> No need to go to Rijeka as there are now other ferry crossing opportunities:

1. Start from Dubrovnik by ferry to Split https://www.croatiaferries.com/dubrovnik-split-ferry.htm
2. from Split get on a bus to Zadar
3. from Zadar get on the ferry to Pula https://www.croatiaferries.com/zadar-pula-ferry.htm
4. from Pula take ferry to Venice https://www.croatiaferries.com/pula-venice-ferry.htm

Getting from Venice to Dubrovnik article may add some insights:

Getting from Venice to Dubrovnik