More than seven in 10 voters say Australia Day is important to them but a majority of the population can't accurately name the event it commemorates, new polling has revealed.

When a representative sample of voters was asked to identify the historical event marked on Australia Day from a list of six possible alternatives, only 43 per cent correctly named the landing of the First Fleet at Sydney Cove in 1788.

One in five said Australia Day commemorated the discovery of Australia by Captain Cook while one in six said it was the anniversary of Federation. Smaller proportions said the national day marked the date of a treaty with indigenous people (7 per cent), the date Australia stopped being a colony of Great Britain (6 per cent) or the date of an important battle in World War I (2 per cent).