Topsail is a defunct provincial electoral district for the House of Assembly of Newfoundland and Labrador, Canada.

The residential mix was suburban and sometimes rural, although many residents had commutes to St. John's.

Topsail was created in a 1995 redistribution, incorporating much of Conception Bay South and a small part of Mount Scio-Bell Island.

The district also gained 16 per cent of both Waterford Valley and Conception Bay East-Bell Island.

In January 2010 Prime Minister Stephen Harper appointed Marshall to the Senate of Canada.