Hotel in Athens after arriving in the evening by air and solo

No question - Peri’s Hotel. They picked us up at the airport when we arrived at night, and also phoned a restaurant to have dinner delivered, which we ate at a table in our room. We were a couple, but they’re close to the airport, no need to go outside, and we got a good night’s sleep.

They also drove us to the port for our ferry the next morning, but I’m sure could assist you with getting to your bus.

Do you take a bus from the Kifissou cenrtal bus station where the buses leave for Nafplio?

In this case your best option is to go to Athens where you will find hotels of all categories and then take a taxi or the metro the next day to go to the bus station.
The Peri's hotel is not in Athens but in Artemida, a small town almost 30 km from the bus station!

If you take a bus with an organized tour it will also probably leave from the city center. So no point in going to Peri's hotel either

9:30 p.m. is not too late in Greece in general or Athens, it's the time when the Greeks go to dinner.
Arriving at 8:30 p.m. you will leave the airport less than an hour later. There are buses, the metro or taxis to go into town.

Any hotel near the airport will be far more expensive than many in Athens.

If you are concerned about safety that time of night then book a private transfer with a company like Welcome Pickups or Uber. They'll wait at the airport and drop you off at your hotel.

Numerous accommodations all over Athens.

You can then take a taxi from your hotel to the bus station to Nafplio. They'll be numerous buses so you should be able get one without a problem.

Paige, a lot depends on dates & budget; you get best help if you provide these, because it can make a BIG difference --

NEAR AIRPORT #1 -- Peri's is a modest place used to be about (€75-80) as noted no dinner, but can have a pizza delivered to your room, not that festive, but nutritious. They have continental breakfast I think, and can shuttle you back to the airport (without charge I believe). At Airport, 24/7, every 20-25 minutes an X93 express bus (€6) goes to the KTEL Kifissou Bus terminal for the Nafplio Express bus (takes about 1 hour outside of rush hours).
NEAR AIRPORT #2 -- Hotel Avra free shuttle to/from (IF u book at same time as room); 25min ride, to Village of Rafina...hotel is 200 yards from small shady town square w many cafes for a light meal; hotel has cafes. main diff to Peri is single room maybe 50% more. Same x93 bus from Airport in AM, to Get Nafplio bus.

CENTRAL ATHENS OPTIONS: INTO central Athens, then AM Taxi to The Nafplio Bus terminal. Options & costs

(1) Book a Car service online either Welcome Pick-ups or City Cab, (which is really a car service) ... charge ulntil Midnight is about €40 flat-fee to central athens, pay by credit card, driver meets you aat baggage claim with your name on card. (There is a taxi line w same rate, but sometimes drivers try to scam newcomers)
(2) From Door 5 of Airport, take X95 Express bus to Athens Central Square, Syntagma; leaves every 20-25 minutes €6, takes about 1 hour. Upholstered seats, luggage piled in central "Pen". Stops right at Curb on square. Very handy, IF you can book room nearby. Handy moderate hotels (under $100) just off square = Hotel Arethusa Hotel Pan, Best Western Amazon, Achilles and Hermes. NOTE: if yours is a weekend date early Sept, hotels may already be full... Sept is busy month for Greek doings in Athens

NAFPLIO - Nafplio express bus goes every 2-3 hours, on half-hour. (It costs about €15 one-way now I think). Reserved seats, upholstered comfy, ask for LH side for views of sea enroute. Ask your hotel to call Station night before & get timetable & plan to get there 30+ mins before; taxi about ?17? 20?. Nafplio tix (unlike other destinations), sold at table by bus -- which iis located by an exit door. Do breakfst before - bus station food is grim of course. When u get to Nafplio, decide what time u want to return & buy ticket then.

These are super helpful tiips! Thank you all so much. Love Rick's Forum

This is a big birthday trip for me so cost is not as much an issue as ease and convenience. Not too worried about safety but am looking for things to be easy when I arrive after a long flight. :)

Happy Birthday in advance! I think Peri’s is closer now to €100 or €105 a night, maybe less for a single. If cost isn’t a huge concern, then it’s not an issue, but their convenience is priceless! :-)

IF car service to Central Athens not a concern, nor 1-night Hotel room, then many other options for convenient hotel ... Some midprice that are south of Acropolls, convenient & peaceful, include Airotel Parthenon, Hotel Hera, Hotel Herodion, Hotel Phillipos all are full service w breakfast & deska will call bus station for info & get taxi to get there.

I agree with Janet for the central Athens option, much easier to reach from the airport whether by taxi (45 minutes - 40€) , bus (55 minutes - 5.5€) or metro (40 minutes - 9€), and to go to Kifissou Bus station the next day.

Plenty of hotels at all prices near Syntagma Square, around the Acropolis in the districts of Plaka, Thissio, Historical Athens, Psyri...

The bus station is a little away from the center of Athens (4 km) in an area that is not glamorous at all, and without hotels.
You could go there by public transport but prefer a taxi. Ask your hotel to call one.

And by the way, happy birthday....

Even if the first name doesn't match... https://www.youtube.com/watch?v=ijQG62H4vcY