Edmonton-Castle Downs is a provincial electoral district in Alberta, Canada. The district is one of 87 mandated to return a single member to the Legislative Assembly of Alberta using the first past the post method of voting.

The Legislative Assembly of Alberta is the deliberative assembly of the province of Alberta, Canada. It sits in the Alberta Legislature Building in Edmonton. Since 2012 the Legislative Assembly has had 87 members, elected first past the post from single-member electoral districts. Bills passed by the Legislative Assembly are given royal assent by the lieutenant governor of Alberta, as the viceregal representative of the King of Canada. The Legislative Assembly and the Lieutenant Governor together make up the unicameral Alberta Legislature.