One of the main sights of Lerici is its castle which since its first founding in 1152 was used to help control the entrance of the Gulf of La Spezia. Today the castle contains a museum of palaeontology.
The origins of the town date back to the Etruscan period. In the Middle Ages the town came under Genovese control. After it had been sold to Lucca, it became involved in a series of conflicts between Genoa and Pisa, as it was on their common border. In 1479, the town came under Genovese sway for good.
Italian author Mario Soldati had a residence in the frazione of Tellaro.
Italian painter Oreste Carpi spent many years in San Terenzo making hundreds of paintings and drawings reproducing town landscapes. English writers Mary Shelley and Percy Bysshe Shelley lived some three miles north in an isolated old boat house called Casa Magni, and anchored their sailing boat in Lerici. Their closest neighbours were the villagers of the tiny hamlet of San Terenzo. Percy Bysshe Shelley drowned on 8 July 1822 in the Bay of Spezia, returning to Lerici from a journey to Leghorn and Pisa. His corpse eventually washed up on the beach at Viareggio, located approximately halfway between Livorno and Lerici. The popularity of Lerici with the Shelleys and with Lord Byron earned the Golfo di Lerici its title of the Golfo dei Poeti, the Poets' Bay.
Hungarian author Baroness Emmuska Orczy, author of The Scarlet Pimpernel had a villa built in the hills above Lerici, near the locality of Bellavista, and called it La Padula. Orczy and her husband Montague Barstow spent several months there in the 1930s – alternating between La Padula, Villa Bijou in Monte Carlo, and trips to Britain. Eventually they decided to abandon fascist Italy for Villa Bijou. La Padula still stands today.
Lerici is one of the mariner communities which take part in the Palio del Golfo, a rowing contest held in La Spezia every first Sunday of August.
Lerici is also twinned with Horsham, in Great Britain, although the latter no longer records this as an "active" twinning on its official website. Horsham is where Shelley was born, and Lerici where he died.