The Steam Packet Company said 36,500 people have so far travelled for the event, compared with 35,500 in 2016.
Last year's figures suffered a hit due to the unavailability of a fast ferry serving Northern Ireland.
Chief executive Mark Woodward said demand to travel during the TT remains "extremely high."
As well as the 36,500 passengers, the company said it had carried 14,037 motorcycles and more than 4,000 cars, vans and trailers.
Hundreds of passengers were stranded on the island this week after high winds cancelled sailings on Tuesday and Wednesday.
However, the majority were given bookings on alternative sailings within 24 hours.
The TT festival, which sees racers from all over the world reach speeds of 200mph on closed public roads, will conclude with the Senior race on Friday.
Races were cancelled on Thursday due to heavy downpours.
The number of ferry passengers heading to this year's Isle of Man TT Races have recovered following a downturn in business last year.