Two databases from two sources.
1. IFES Election Guide
Global elections database, interactive map, RSS updates, and more from the International Foundation for Electoral Systems (IFES). Users can register (not a requirement) and create a personalized election guide.
Direct Links to Upcoming and Past Election Info
IFES Election Guide on Twitter
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2. Global Elections Calendar
Searchable database of upcoming and past elections info provided by the National Democratic Institute. Data back to 2005.