Venice to Cinque Terre

Well, it's 5 1/2 to 6 hours from Venice Santa Lucia to Monterosso. Go to trenitalia.com for info and tickets. You could certainly stay someplace in between, say Florence or Lucca. (It's about 3 hours from Florence to Vernazza in the CT.)

It is about a 5.5 to six hour trip from Venice to the CT with usually a couple of train changes. No real need to overnight anywhere. If you leave Venice in the morning you can be in the CT by early afternoon to late afternoon depending on when you leave. Where a stop might make sense is where you are going to after the CT. If you are continuing on the Florence, to me it makes more sense to put your Florence time in between Venice and the CT. That way you have a 2 hour train ride from Venice to Florence. Then a 2.5 hour ride to the CT after your Florence excursion. If you are not going to Florence then just take the big travel day all at once.

Thanks so much for your help. This is comforting to know that we can make this trip all in one day; now I will know how to proceed with planning. After the CT, we are heading via train to Nice where we will home base for about 4-5 days and do day trips in that area. Then on to Auzon and then we'll end up in Paris for the last 3 -4 days.
Once again, thanks for any suggestions.

We've done the trip in the opposite direction. We departed La Spezia before 7:00am and we were looking at the Grand Canal at 2:00pm. We had all of the remaining afternoon to tour and check-in to our hotel. You can easily do the same in reverse. Its not that bad. Going to Nice Ville, the train travel time will be just over 5.0hrs as well.

Thank you so much for your prompt and helpful advice. I now look forward to making the trip to the CT all in one day.