Vonn finished 0.70 seconds clear of Switzerland's Lara Gut, with Austrian Cornelia Huetter a further 0.55 seconds back in Altenmarkt Zauchensee.
The American also won Saturday's downhill event.
That equalled Annemarie Moser-Proll's record tally of 36 World Cup downhill wins.
The 31-year-old now has 73 overall World Cup wins - 13 short of Ingemar Stenmark's record.
Vonn leads the World Cup super-G standings by 80 points over Hutter, and is now within 38 points of Lara Gut in the overall standings.
"It's a perfect start to the new year," she said. "Hopefully I can just continue on in this direction and keep winning."
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Lindsey Vonn claimed her second win in two days at the Alpine Skiing World Cup event in Austria with victory in the super-G event.