Monitoring at 84 designated swimming beaches shows 72 are on track to meet European water quality standards for 201 - five more than in 2016.
The number receiving the highest grading has also jumped significantly, rising by 53 per cent.
Test results suggest 17 more areas will be rated as ‘excellent’ when EU classifications are confirmed next spring.
A total of 62 beaches will be classed as ‘good’ or ‘excellent’ and 10 ‘sufficient’ as the new bathing season begins in June.
Despite an overall improvement in water quality across the country, however, 12 sites remain in the ‘poor’ category.
The findings have been released by the Scottish Environment Protection Agency (Sepa) to conform with standards set by the Bathing Water Directive, which came into force last year.
This is the second bathing water season under the new rules, with classifications based on the overall number of bacteria counted at beaches over a four-year period.
“It is good to see that an initial analysis of the classifications for 2017 shows a reduction in the number of bathing waters classified as poor and a general improvement across the other classifications,” said Calum McPhail, from Sepa’s environmental quality unit.
“We understand that some local communities will be disappointed, as we are, that there are 12 bathing waters which are expected to be rated as having a ‘poor’ EU classification.
“We would like to remind the public that a ‘poor’ classification does not necessarily mean that water quality is continually poor, and that these are still fantastic beaches to visit.
“Since Sepa’s regulation and monitoring of EU bathing waters began in 1988, Scottish bathing waters have been increasing in number and improving in quality. ”
Environment minister Roseanna Cunningham, added: “It is extremely encouraging to see an increase in the number of bathing waters classified as ‘excellent’ and a drop in those classified as ‘poor’.
“We must build on this progress, working toward all of Scotland’s bathing waters achieving the ‘sufficient’ standard or better.
“Bathing water improvement plans are underway and Sepa, Scottish Water, land managers and local community groups have been working together to improve water quality.
“We will continue to collaborate on improvements and I would encourage local communities to get involved with this important work, which is at the heart of beach tourism and the economies it supports.”
As well as tighter standards, the EU directive requires information provision for beach users.
Sepa operates a daily signage network and provies real-time water quality data for 29 locations during Scotland’s official bathing season, which runs from 1 June to 15 September.
Beaches Rated Excellent
Anstruther (Billow Ness)
Crail (Roome Bay)
Elie (Harbour) and Earlsferry
Elie (Ruby Bay)
Largs (Pencil Beach)
St Andrews (East Sands)