In a 2010 survey, readers of the Danish newspaper Kristeligt Dagblad voted Ærø as Denmark's third most wonderful island, behind only Fur and Læsø.

Ærøskøbing, with its narrow lanes and picturesque 18th-century houses was historically Ærø's chief town, and remains the primary port for ferry connections.

Marstal, also known as the "skipper village", from its being the home of so many sailors and captains, is the island's largest town today and is its principal commercial and shopping centre.

The countryside is for the most part gently undulating, and there is a several-kilometre-long stretch of 33-metre-high cliffs at Voderup Klint on the west coast.

At Olde Mølle, at one of Ærø's highest points and near the centre of the island, the sculptor Erik Brandt has created a "peace bench", conceived with the intention of providing people with an opportunity to survey the island and its surrounding sea, whilst pondering on the theme of world peace.

In 1750 the island, previously split into exclaves of numerous duchies, was united as single administrative district.

When Duke Christian died, Ærø was distributed among four of his brothers, and this offers one explanation of why two towns developed in the island, Ærøskøbing and later on Marstal, and why each came to be in their own "country".

[citation needed] In recent history, the preservation of the area's local heritage has been paramount among residents.

As of January 2013, the area of the island's large solar power plant was expanded from 18,365 m2 to 33,300 m2 as a result of an extension under the Sunstone 4 project.

From August 2019, the island has been served by the E-ferry Ellen, an innovative low weight ferry[4] for cars and passengers, powered by green electricity stored by on-board batteries.

Built by Søby Værft, the ferry's design is well beyond state-of-the-art in terms of charging power and operating distance.