Barrhead Travel said enquires had nearly doubled already amid a surge in interest, with Tenerife, Orlando and Barbados among the most sought-after destinations.
Airline Jet2 said a 150 per cent rise in bookings had returned them to pre-pandemic levels.
The operator said mainland Spain, the Canaries, the Balearic Islands, Turkey, and Greece were among the most popular choices.
The surge came as fully-vaccinated people returning to the UK from Friday no longer needed to take a Covid test before travelling and will not need to self-isolate until they receive a negative test result after arrival.
In addition, from Sunday, the requirement for a PCR test within two days of arrival will be replaced with a cheaper lateral flow test, but again only for those fully-vaccinated.
However, the body that represents Scottish travel agents said despite the increase, they were still trading at only just over half of pre-pandemic levels.
The Scottish Government also urged caution over foreign travel.
Transport secretary Michael Matheson warned: “People still need to be extremely careful when travelling and to remember that both our and other countries' Covid-19 requirements can change at short notice as things can evolve very quickly.
“People should therefore ensure they have travel insurance and carefully check their booking terms and conditions, as well as ensuring compliance with the latest regulations for the country being visited.”
Barrhead Travel president Jacqueline Dobson told The Scotsman: “This week our enquiries have grown by almost 100 per cent, demonstrating that demand for holidays is fast returning.
"We expect a busy weekend across our stores, particularly as holidaymakers are increasingly seeking the expertise of a reputable travel adviser.
“Summer 2022 is our most popular booking season, while one in five new bookings are currently for departure before the end of March.
"However, we expect to see last-minute holidays accelerate over the coming weeks thanks to the relaxation of testing rules.
“Our top destinations include Tenerife, Orlando and Barbados – but there has also been a sharp rise for other US destinations such as New York and Las Vegas for departures this year.
"The airline sales are offering very attractive prices and we’re seeing some really strong pricing from our operator partners.
"Our advice to those looking to travel this spring or summer is to book now while pricing and availability remains buoyant.”
Mike Tibbert, president of the Scottish Passenger Agents’ Association, which represents the travel sector, said: “Even at this early stage, our members are telling us that enquiries are up over 100 per cent on the previous week and bookings are showing similar levels of growth.
“Travel agents across Scotland are looking forward to a busy weekend as customer sentiment towards travel increases in positivity.
"These changes are good for our whole sector.
“However, it should be remembered that, although a 100 per cent increase in enquiries and bookings looks significant, the base figures were very low after two years of incredibly poor trading.
"They are, in fact, around 60 per cent of the levels they were trading at in a similar period in 2019.”
Jet2 and Jet2holidays chief executive Steve Heapy said: “The relaxation of travel restrictions is welcome news for both the travel industry and Scottish holidaymakers, and comes during what is traditionally a very busy period for holiday bookings.
"We have seen an immediate and dramatic spike in bookings, with volumes since the Government announcement heading towards pre-pandemic levels, which demonstrates just how much demand is out there amongst people in Scotland wanting to get away for a much-needed holiday."
In announcing the easing of restrictions on Thursday, Mr Matheson said: “Given the rapid spread of Omicron last year, it was essential that we took immediate steps to protect public health in Scotland, particularly with regards to international travel.
“We still have significant concerns over Omicron, but we recognise that, now it is the most dominant strain in Scotland and across the UK, it is sensible to review the measures currently in place.
“We also fully understand the impact of the restrictions on staff and businesses in the travel and aviation sectors and these changes demonstrate our commitment not to keep measures in place any longer than necessary.”
The boost in demand for holiday bookings came as Scotland recorded 15 coronavirus-linked deaths and 14,486 new cases in the 24 hours to Friday.