We have done this a few times and each time took a Midland train from Euston Station. The last time was in 2022. I recommend using the Google Maps app and the Tfl Go (London Transport) app while in London. It looks like Euston Station is a 15 minute walk from your hotel (or you could Uber there). We always purchased tickets for the first HP studio tour entry time to beat the crowds inside (better and easier pictures!). My recollection is that the commercial bus services either didn’t get there early enough and/or you had to stick to their schedule for your return.
My notes are below:
Getting to Studio Tour from London by Train & Bus:
The nearest train station is Watford Junction which has a direct train from London Euston station taking 20 minutes. There are several trains per hour.
Take the Tube and get off at Euston. Go upstairs (just a few stairs and then 2 escalators) and you go straight up into the station. Ahead of you is a huge departure screen showing all the trains leaving in the next hour or so. Look for a London Midland train which shows that it stops in Watford Junction. Don't look at London Overground trains. They are too slow. London Midland trains with the destination of Tring, Milton Keynes, Northampton, or Birmingham will stop at Watford Junction, and will get you to Watford Junction in 20 minutes plus or minus. Always check the departure board to make sure of the Watford Junction stop. Use your Oyster card, or you can buy tickets from the ticket office, but expect a queue.
When you get to Watford (depend on which service how many stops, no more than 3) follow the crowd to the front of the station. Go outside and just across the drive, just to the left is the stop for the bus to the studio. It is very clearly marked, and when the bus arrives it will be very well marked, and you won't be the only tourists heading for it.
From here, there is a shuttle bus run by Mullany’s Coaches which goes from Watford Junction Station to the studios. The journey takes about 15 minutes.
Shuttle buses run at least every 30 minutes from 8.15 am when the first tour is at 9 am.
It’s recommended to arrive at Watford Junction Station 45 minutes before your tour begins.
This is the information from the WB Studios website:
GETTING HERE
SHUTTLE BUS FROM WATFORD JUNCTION
Your journey to the Studio Tour is carbon-free as our buses are powered by electric. This journey is included as part of your entry ticket.
Regular shuttle buses operate from Watford Junction to the Studio Tour with a journey time of around 15 minutes. Buses run at least every 30 minutes from 9.20am (with additional services available from 8.15am when the first tour is at 9am). The last return shuttle bus back to Watford Junction will depart the Studio Tour when the Tour closes. For more information regarding this, please see the
opening times calendar.
Please note, e-scooters are not permitted on our shuttle bus or on-site at the Studio Tour.
TRAVELLING BY TRAIN
The Studio Tour’s nearest railway station is Watford Junction and direct services arrive there from both London Euston (20 minute journey) and Birmingham New Street (1 hour journey).
Other non-direct train services operate from London Euston, but please be aware that these may take longer to arrive at Watford Junction. Oyster cards are valid between London Euston and Watford Junction.