Padua to Marco Polo Airport

There are a bunch of different ways to solve this. The biggest question is what time of day...

I would be tempted to take the train to Mestre and then hop on a bus there.

http://www.veniceairport.it/en/transport/venezia-mestre-station.html

But, as you can see in the left column of the above web page, there is an entire page dedicated to Marco Polo to/from Padua.

While in Venice/Padua, don't forget to check out Vicenza!

Good luck.

There is an hourly bus - in the morning even half-hourly - leaving from the bus station in front of the railway station. Best to check the times at the bus office. I used it once, and found it very convenient.

We've taken that bus on the reverse route - Marco Polo airport to Padua. It's an easy connection. Enjoy your time in Italy!

I also had no problem taking the bus in from the airport to Padua and therefore decided to also use that bus when moving on to Venice.

We've also taken the bus the reverse way, Marco Polo to Padua. Pleasant, easy trip. The bus stop is right outside the airport terminal. At the Padua end, it stops very near the train station.

We had planned all along to take the bus from Padua to Venice airport but near the end of our stay saw a brochure for car service in the hotel lobby. We “debated” this extravagant suggestion for some time, but I’m glad we did as it made the departure morning so much simpler, door to door, on time, no hassles or surprises.
I can also suggest the Hotel Al Cason in Padua. It is near the train station, not the most charming area, but we felt safe and it was very convenient to the station and city bus. Not “old worldy”, modern, spacious room and bathroom. Family owned and operated, they were gracious, kind and helpful. Small bar and restaurant nice to return to after daytripping or visiting Padua. Safe travels.