Officers stopped a Polish registered truck which came on a ferry from France and found the cigarettes within its load.
They have a retail value of €2.4 million, which is a potential loss to the exchequer of over 1.8 million.
A man in his 40s is being questioned as part of the investigation.
Irish Coast Guard, RNLI and Water Safety Ireland urge everyone to 'Unite to Turn the Tide
July has been one of the busiest months in years for rescue services, with warm weather bringing more people to Wicklow beaches, rivers and lakes.
Bray Wanderers Head To Cobh Amid Apparent Cross-Channel Interest In Seagulls Talent
New Laws Boost Protection In Wicklow Mountains National Park
A dedicated National Parks Bill will put nature conservation first and help manage growing visitor numbers.
Woman Dies In Waters At Wicklow Beach
The incident occurred on the outskirts of Wicklow town, near the Blainroe golf club.
Wicklow Housing Remains Ireland's Most Expensive Outside Dublin
Strong demand, low vacancy and limited housing stock are keeping county prices elevated.
6:00am - 8:00am
The Wicklow Way with Nikki Hayes
Heavy rain shower
High: 21°C | Low: 13°C
Heavy rain shower
High: 21°C | Low: 12°C
Heavy rain shower
High: 21°C | Low: 11°C
Heavy rain shower
High: 19°C | Low: 12°C
Heavy rain shower
High: 20°C | Low: 12°C