Day trip to Sintra from Lisbon: Best small group/private tour?

Pardon me for not answering your question, but we were there recently, and in my opinion, a guide/tour is not necessary. Good bus service is available...take a taxi if you wish. Rick's information is worthwhile. Sintra is a beautiful small city.

I appreciate your response, Bruce, and you may be right in general, but we'll be near the end of a long trip and ready to be driven and guided by that point. Others?

We were in Lisbon last fall and stayed at Casa Amora Guesthouse. Juan, the innkeeper arranged a private tour for us with Ricardo and he was a terrific guide. We visited Sintra, Cascais and had lunch at a local seafood restaurant on the coast. We felt that it was a very worthwhile experience as he also took us to other places "off the beaten track". I don't believe that Ricardo works exclusively with the guests at Casa Amora, however I can't say that for sure. You might try contacting Juan to see if he could put you in touch with Ricardo. Sorry that I do not have the contact info for you myself, as I highly recommend him! http://casaamora.com/en/contacts

CoolTour Lisbon does a nice tour of Sintra, stopping on the way back to Cascais for a brief time. It’s reasonably priced and I enjoyed it when I first moved here. And, yes, while you can do the trip on your own, there are times when it’s nice to not have to think about where to go, how to manage your time, etc.

I am planning a trip from Lisbon to Sintra to stay 1 night what is the best mode of transportation to get to Sintra use a Uber or take the bus or the train?

The train is convenient and cheap. You can easily walk from the Sintra train station to the center of town.

We took an amazing small group day tour a couple of years ago (8 of us) with Lisbon Riders (Viator). The name of the tour is "Sintra and Cascais Small Group Tour." Well worth the investment. One of our all time favorite tours. The meeting location was at Praca da Figuera, a short walk from our hotel.