York is 97 kilometres east of Perth — about 90 minutes by car. Take the Great Eastern Highway (National Route 94) from the CBD through the Darling Ranges and into the Avon Valley. The drive is part of the pleasure: the ranges are scenic, and you drop into the valley with a good view of the wheatbelt country opening out ahead.
There is no regular passenger train service to York. Transwa operates a bus coach service from Perth's East Perth terminal on select days; check the Transwa website for current timetable. The service is infrequent, so most visitors drive.
If you are doing a day trip, York is easy to combine with a stop in Northam (40 minutes further east along the Avon) or a return via Mundaring and the Darling Range.