It is part of the ancient parish of North Meols and was formerly a detached settlement, on the northern fringe of what is now Southport.

Marshside's most notable features are neighbours: the SSSI and nature reserve on the opposite side of Marine Drive.

Marshside was a local centre of the Temperance movement, and the Marshside Temperance Hall on Shellfield Road, built 1884 and rebuilt 1934, is a registered charity (Charity number: 233530), which continues to host community events, including the Tuesday Club which has been running for over 100 years.

Marshside has surprisingly few pubs (compared with neighbouring Churchtown), possibly in part due to the strong tradition of Methodism and Temperance in the former village.

In the early twentieth century, Marshside had its own completely unique dialect feature, involving a parasitic nasal consonant, occurring after certain final consonants, mostly plosives, in words at the end of a sense group, and before the plural inflexion [z] medially and at the end of a sense group.