She says her party is on the verge of what she calls a major-major breakthrough and she thanked volunteers for helping to make it happen.
Notley joked that she expects much of her day will be spent keeping emotions in check.
Alberta voters are picking a new government, and campaign polls have suggested the NDP could come out on top.
Progressive Conservative Leader Jim Prentice was upbeat as he voted with his wife Karen in Calgary-Foothills.
Liberal Leader David Swann also voted in Calgary, while Wildrose Leader Brian Jean was to cast his ballot in Fort McMurray.
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