The Scottish Environment Protection Agency said all 83 beaches achieved a European mandatory standard and 47 (57%) additionally gained the stricter guideline standard.
It is the first 100% pass rate since 2006, when Scotland also experienced a dry summer.
VisitScotland said the results were great news for the Scottish tourism industry.
A VisitScotland spokesman said: "This is a massive endorsement of the water quality at beaches around the country. This is the Year of Natural Scotland and it's great to see everyone getting behind the initiative and supporting our wonderful scenery and landscapes.
"This summer has been fantastic and has clearly had a positive impact on bathing waters.
"This sends out a strong message to visitors that our waters are safe, which can only be a good thing for tourism in Scotland."
Environment Minister Paul Wheelhouse said a lot of work had been carried out by the Scottish Government and SEPA to improve water quality.
"This work will continue, to ensure that, in future, families can enjoy a day at the beach and have confidence in the quality of the water," he said.
SEPA has taken 1650 bathing water samples over 107 days since the season began on June 1, with most being tested 20 times, and only eight individual samples exceeded the limits and failed to reach mandatory level (0.5%).
EU rules mean that if bathing water sampling fails more than once at the monitoring location, then it has failed overall compliance at the end of the season.
Three samples were also taken on dates when SEPA predicted poor water quality due to rainfall, and were discounted as appropriate electronic signage was in place advising against bathing.
Beteween July 25 and July 31, SEPA declared an "abnormal situation" for Stonehaven bathing water and issued appropriate signage warnings in line with regulations following a lightning strike damage to a sewage plant.
Calum McPhail, environmental quality manager for SEPA, hailed the results as the best year on record because this year's inspections included 20 more bathing waters that were not considered in 2006. He also pointed out that this year an even greater proportion of bathing waters reached the highest guideline standard.