You can get in to Kuwait by plane, by car or bus and even by boat.
Kuwait International Airport is the only airport in Kuwait. The national carrier is Kuwait Airways and it caters to London, New York, Paris, Geneva, Frankfurt, Rome, Kuala Lumpur and several other destinations. The international airlines getting you to Kuwait are British Airways from London, Lufthansa from Frankfurt, United Airlines from Washington DC, Thai Air from Bangkok, KLM from Amsterdam, Singapore Airlines from Singapore, Turkish Airlines from Istanbul. There are seasonal flights going to Kuwait as well, such as Malaysia Airlines, Bulgaria Air and Czech Airlines.
The popular bus services in Kuwait include KPTC, City Bus and KGL. Long-distance bus services exist to Dammam and other areas in Saudi Arabia but for this, a valid Saudi visa is required.
Kuwait has shared borders with Saudi Arabia and Iraq. The King Fahad Bin Abdul Road is ideal to get to Kuwait from Saudi Arabia, so you can drive in from there.
The Kuwait-Iran Shipping Company operates ferries to and from Iran. These ferries operate thrice a week, between Ash Shuwayk in Kuwait and Bushehr in Iran. There are also speed boats between Ash Shuwayk and Bahrain.