She sent the tweet after Labour leader Jens Stoltenberg used Twitter to ask former Prime Ministerial staff if anyone remembered his special recipe for herring salad, an important part of the traditional Norwegian Christmas spread.
"I can't find my special recipe for herring salad in the moving boxes," Stoltenberg tweeted. "Does anyone remember it?"
Solberg quickly tweeted back. "Hi Jens, I have not found any herring recipes in the Prime Minister's residence :)".
"The winner of this year's post / tweet works on many levels," the jury said in a statement accompanying the award. "It is spontaneous, shows humour and has a bite. After an intense campaign, thrilling duels, and a hard fall, this tweet is a charming testament to an open Norway. A funny little thing that showed how politicians can joke together even if they are political opponents."
The awards are part of the Social Media Days conference, held in Oslo on February 3-6.
Solberg thanked the jury for the award over Twitter, apologizing that she couldn't be present.
.@jensstoltenberg hei Jens, jeg har ikke funnet sildeoppskriften i Statsministerboligen :)— Erna Solberg (@erna_solberg) December 21, 2013