Erna Solberg, the safe choice
A native of the west coast town of Bergen, the portly, 56-year-old blonde has been prime minister since 2013, in a minority coalition with the anti-immigration Progress Party.
Dubbed "Erna the Star" for her praised handling of two major challenges -- the migrant crisis and the tumbling oil price -- Solberg now hopes to do what no other Conservative has done in over 30 years: win a second straight mandate.
"We have demonstrated over the past four years that we know how to handle difficult crises," she said during the campaign, presenting herself as the election's safe bet.
"Unemployment is on the way down, growth is on the way up and we're creating more and more jobs," she said.
Phlegmatic, composed and knowledgeable, Solberg has dedicated her entire career to politics.
First elected to parliament at the age of 28, she went on to earn the nickname "Iron Erna" when she showed herself to be a firm minister of local government charged with immigration affairs in 2001, a post she held until 2005.
That year, she came close to being kicked out as head of the party just one year into the job, after the Conservatives posted a catastrophic score in legislative elections.
But she softened the party line, putting the accent on social issues. "People, not money" became her leitmotif.
An avid gamer, she has refused to kick her habit even after becoming Norway's second female prime minister following Gro Harlem Brundtland.
Jonas Gahr Støre, an heir battling inequality
Elected to the head of the Labour Party in 2014 after an unusual reverse social climb, Store follows in the steps of his mentor and friend, former prime minister Jens Stoltenberg.
At 57, the slender, greying and eloquent politician is seeking to topple the outgoing coalition by vowing to beef up the welfare state by reversing some tax cuts introduced by the current right-wing government.
Store held key portfolios in Stoltenberg's cabinets, serving as foreign minister (2005-2012) and health minister (2012-2013), earning generally positive reviews.
When Stoltenberg left Norwegian politics to become NATO secretary general, his protégé Støre succeeded him as head of Labour, the party that has dominated Norway's post-war political scene.
His political career illustrates his reverse social climb. His tidy fortune -- inherited from his family's fireplace business -- his elegant technocratic air, and even the fact that he speaks French after studying political science in Paris all worked against him, especially among the party's most left-wing faction.
To mute critics, he now makes a point of raising the Norwegian flag on May Day.
Even so, some still think he has "the air of a right-winger."
While the Labour Party long enjoyed a comfortable lead in the polls, it has struggled as voting day approaches and will likely be dependent on smaller opposition parties if it hopes to seize power.