Flight or Train from Rome to Venice

Assuming you have luggage checked there is no way you are making a 10:10 AM flight.
If no checked bags and coming from the US still no way to make it since you have to pass through immigration.

If you are coming from another Schegen country as part of your flight and have no checked bags, maybe but there is some risk.

I think waiting for the 2:30 flight makes the most sense

Well you didn't give us a date so we could verify your findings and your finding of only 2 flights on your particular day is rather curious. Assuming you're flying FCO -> VCE there are several airlines that have direct flights including BA, EasyJet, Etihad, Tarom and a plethora of airlines that have indirect routes from FCO -> VCE.

I would definitely wait for the 2:30 flight and spend the excess time relaxing, getting a bite to eat, getting some Euros from an ATM machine and waiting for your bags. Even assuming your flight arrives on time, you'll have to check in 40 minutes before the flight to Venice is scheduled to depart which means you'll only have 15 minutes to get off the plane, go through customs and immigration and get from one gate to another. You can check on Google Flights to see if other airlines might have an earlier flight than Alitalia. Though you might get to Venice a little sooner by taking the train, I would avoid the hassle, and expense, of getting to Rome, changing trains and going by rail. You're on your honeymoon. RELAX! Dolce far niente.

I would also look at flights to Treviso airport.
Not quite as convenient/close as VCE but might have better times and be able to get you to Venice faster in the end.

personally, I would take the train. Why not sit comfortably and enjoy seeing the Italian countryside as you roll on

No way to make the 1010 flt

In your particular circumstance, flying seems a good choice. You are already at the airport.

Unless train is WAY cheaper, I would fly. ( on expedia I see a $51 fare for mid-august I would get it before its gone.. )

First of all, congratulations!

Regarding your question - absolutely take the train!!! There's a direct Frecciargento departure (no changes) from Roma / FCO at 11:08 and you should have no trouble connecting with that. That's a high speed train, travel time is a relaxing 4H:27M, and you'll arrive at Venezia Santa Lucia at 15:35, which is a good time to arrive. Check into your hotel, have a brief walkabout, a fine hot meal and then retire early to get over jet lag. I doubt if a flight will save much (if any) time.

Travel by train will be much more pleasant, you'll be able to have a nap, enjoy the scenery or just enjoy being in Italy. You won't have any hassles with luggage size or weight, which will be a factor if you use a flight. Be sure to watch your luggage carefully if it has to be placed in the luggage rack (don't leave it unattended).

completely agree with Ken

Have done both in the past two years. Definitely fly!

Took the train first year, plane was late and missed the only direct train. Ended up changing trains at Tiburtina station, bags off then on another train. Just a pain.

Last year flight. Wandered around Fco, had a leisurely lunch, checked in. Arrived VCE and took the Alilaguna to Venice. While it doesn't save more than a half hour, it allowed us some down time we needed. ✈️

I agree with Ken. You'll have some downtime on the train, and it stops at the Grand Canal, so your first view of Venezia is amazing.

Personally, waiting for a plane connection stresses me out far more than four hours on a train.

Train! I agree with Jim, Ken, Zoe. You will see so much as you roll along.