On-campus: The University of York’s affiliated organisation York Conferences is responsible for allocating B&B style rooms on campus. To book a room on the University of York campus, please do so through the York Conferences website at the link above or call them directly at +44(0)1904 328431. They will be able to handle your booking and answer any queries you may have about staying on campus.
Off-campus (between City Centre and University): There are several reasonably-priced (mostly between £60-70/night) guest houses within a 15-20 minute walk to the University (most of them also within a 5-minute bus ride along Heslington Rd. via the 66 bus), but early booking is also recommended for these:
1. Four-Poster Lodge (Heslington Rd.) NB. Their website is currently resolving a technical glitch but will be back up soon: http://www.fourposterlodge.co.uk
2. Stay City Aparthotels (York Paragon Street): https://www.staycity.com/york/
3. Victoria Hotel, The Old Brewery, (Heslington Rd.): http://www.victoriahotelyork.co.uk/
4. Barbican House & Conway Cottage: https://live.high-level-software.com/hotels/barbican
5. Bull Lodge Guest House (from £30, GBP cash only): http://www.bulllodge.co.uk
York City-Centre: The beautiful, historic city centre of York, (about a 15-minute bus ride or 30-minute walk to the University) offers many accommodation options and attractions.
For more options, see York Tourist Office website or you may prefer to explore accommodation booking websites such as Booking.com, Laterooms.com, and AirBnB.