National Road 91 (Greek: Εθνική Οδός 91, abbreviated as EO91) is a highway in Attica, Greece.

It was first constructed in the 1950s as a one-lane per direction road, but the section between central Athens and Varkiza was later[when?]

[citation needed] Currently, there are no plans to replace it with a bypass or reconstruct certain dangerous parts, but there has been an effort to increase police presence to prevent illegal racing and violation of speed limits which were common phenomena over the last 10 years.

National Road 91 begins in the centre of Athens, and runs southwest to the Saronic Gulf coast at Palaio Faliro.

From Palaio Faliro it continues southeast along the coast, passing along the southern and southeastern suburbs of Athens.