The town pre-dates the Norman invasion, but one of the oldest buildings in Tywyn, the existing Church of St Cadfan dates to the Norman invasion,though its origins are probably much older. It houses an inscribed stone from the eighth or ninth century known as St Cadfan's stone. The inscription on this stone is the oldest known written Welsh. In 963, the previous church on the site was sacked by Vikings. Later, during the twelfth century, the church became the subject of a memorable poem by Llywelyn Fardd. The earliest parts of the existing church date back to the twelfth century, though originally, it had a central tower, but this collapsed in 1693.
Many of the notable characters of Tywyn have had close links with the nearby Ynysmaengwyn estate. The family were notable patrons of poets and writers, and many of the poems written for them have been preserved in a manuscript of cywyddau (British Library Additional MS 14899). Later additions to this manuscript include several eighteenth-century Welsh poems, a few of which mention the Corbet and Owen families of Ynysmaengwyn.
The Corbet family played an important role in Tywyn's development during the eighteenth century. They were responsible for draining much of the salt marsh, or morfa, between the Dysynni river and the town, which significantly increased the land available for farming in the parish. Samuel Lewis' 'A Topographical Dictionary of Wales (1833) reported that horse races were held annually every September on this land by the Dysynni. The raven which is used as an emblem of Tywyn comes from the Corbet family coat of arms (the name 'Corbet' coming from the Norman French for raven).
Today, Tywyn is a friendly seaside resort, which amongst its many entertainments, it boasts the only working Wurlitzer Organ in Wales. It is performed regularly for the visiting public.