Ryanair carried 33.4 million passengers in 2005 in what was an increase of 26 per cent on the 26.6 million passengers it carried in 2004.
The budget airline had a particularly strong December, with 2.833 million passengers carried compared to 2.197 million in December 2004.
However Ryanair's load factor, the number of passengers who travelled as a percentage of the number of seats available, was lower in December 2005 at 82 per cent compared to 83 per cent the year previously.
The load factor for all of 2005 was 83 per cent.
Internet sales continue to be buoyant for Ryanair and accounted for 98 per cent of sales in 2005.
In contrast British Airways, headed by former Aer Lingus chief executive Willie Walsh, revealed that it carried 0.2 per cent fewer passengers in December after demand for flights to the UK and Europe fell compared with a year ago.
The airline said a 3.1 per cent dip in passengers travelling on routes to the UK and the continent offset growth elsewhere in the world, meaning it handled 2.728 million people in December.
But revenues per passenger kilometres flown were 4.7 per cent higher as the number of people travelling in first and business class rose by 9.3 per cent.
BA said its planes were 74.2 per cent full last month compared with a figure of 72.7 per cent at the same stage of 2004.