Between April last year and March this year, average occupancy was just over 80%.
It is the highest percentage since record keeping started in 1999.
Researchers analysed data from 24 hotels with more than 3600 rooms in the city centre.
On nine nights in March, occupancy reached 91%, peaking at 97% on March 15 when the city hosted the British Masters Cross Country Championships, and on March 19 during the European Breast Cancer conference at the SECC.
Glasgow City Marketing Bureau believes the influx of visitors in March was down to a number of key events.
They included GCMB campaigns in partnership with P&O Ferries and Icelandair, geared at attracting short break visitors from Belfast, Iceland and the north of England.
Glasgow International Comedy Festival was also held that month and Michael Buble played the Hydro.
Sean Morgan, managing director of tourism market research specialist LJ Research, said: "Glasgow hoteliers have benefited from an increase in demand of around 5% on 2012/13.
"This is a real result against a backdrop of difficult economic conditions."
Philip Mellor, general manager of Menzies Hotel and co-chairman of Greater Glasgow Hotels Association said: "We are seeing the significant investment that has taken place in Glasgow over the past 10 to 15 years, coupled with the city's growing reputation as a host city for major events and international conferences, reflected in the strength of our hotel industry and the wider tourism sector.
"This will give continued confidence to those breaking ground on new developments coming to fruition in the near future."
City council leader Gordon Matheson said: "This report demonstrates continued leisure tourism growth against a pipeline of increasing accommodation supply and a bumper year which will see the city attract thousands of visitors and delegates to a raft of major events and conferences."