Condor says car ferry passengers numbers from the UK were up by almost a fifth over the peak summer period.
The ferry firm says it transported 1,400 more cars here from Poole in July, August and September.
That is a 19% increase on 2019, and Condor estimates that is 3,500 more visitors to the island than before the coronavirus pandemic closed the islands' borders.
CEO John Napton says that is down to the direct sailings it has been running this year.
"These numbers would not have been possible with the 2019 schedule. We have been able to offer direct sailings from the UK which allow us to carry more passengers at peak times, concentrated around weekends when most people want to travel."
He says visitors are staying longer, benefiting the hotel trade.
It's been estimated that an extra £1.4 million has been spent in Guernsey between the start of July and mid-September by tourists.
Economic Development Committee President Deputy Neil Inder says the numbers from Condor are 'welcome news.'
"Condor’s assessment of the summer season is welcome news and matches our own that 2022 has been a good bounce-back year for tourism; one that leaves plenty of room for optimism for the coming years
Tourists remaining the Island for longer has clear benefits for the economy and is another useful reminder that passenger data alone, as single-source barometer for visitor numbers, is not to be relied on but is rather part of the equation along with occupancy data from accommodation providers and information on the length of stay."
Condor CEO John Napton.
Mr Napton is also reporting an increase in islanders travelling to the UK with their car, and says that winter bookings are 'encouraging'.
"The success of this summer, coupled with positive indicators for next year, offers optimism that 2023 could be a good season for the Islands for UK visitors wanting to travel overseas without any Brexit uncertainty. We will be working closely once again with our industry partners to maximise the opportunity."
Condor's 2023 summer timetable will be available in October.
Talks are ongoing between Guernsey. Jersey and Condor Ferries about future passenger services, with the ferry firm saying earlier this month that it still hopes to add another conventional ferry to its fleet.