Vernon to Honfleur by public transportation

Do you mean you are wanting to go as a day trip, or will be going for longer? To me this seems like a trip where it would make the most sense to rent a car; it's a lot of transfers on public transportation, and only an hour or so driving. There's probably a way to do a bus to Evreux and then another to Honfleur, but I doubt it's with the regularity you'll want.

There is a bus line between Deauville and Honfleur. (line 20)
The journey takes about 40 minutes and the ticket price is €2.10
These are the regional buses that serve Normandy
The website is:

https://www.nomadcar14.fr/fr/

There is a translated version in English (selectable at the bottom of the homepage)

On this page you can download the 2022 summer timetables in PDF files (choose line N°20 in the drop-down menu on the right

https://www.nomadcar14.fr/fr/919-Horaires-ete-du-082F072F2022-au-312F082F2022-inclus.html

Thanks! Not a day trip- staying 4 nights in Honfleur, might day trip one day from there. Glad to know there really is a bus.

Now that I really think about it, renting a car would be best, if I can get up the nerve. Could pick up in Mantes-La-Jolie.

I think a car would be more enjoyable (other than the potential stress of driving!) - it's not far but there are some interesting things in the area - Les Andelys has a medieval castle ruin that's interesting for example. Another option could be to take the train to Rouen, poke around, then rent a car from there.

Thanks, Amy. I was just thinking about having a brief look at Rouen, as it happens.

If you don't rent a car, going via Le Havre is better because Vernon does not sit on the line to Deauville, but on the one to Le Havre (with a change in Rouen, usually). Also, buses from Le Havre to Honfleur are frequent (I think the bus line is no. 39).
But a car would be helpful and driving is stress-free in those parts (wide roads, not much traffic).

Thank you, Balso. I now see that the train to Le Havre is under two hours, whereas it’s minimum 3 1/2 to Trouville-Deauville. I might do the train via Le Havre to get there, then rent a car for a day to explore the coast.