Francois Hollande is set to be sworn in as French president, before travelling to Berlin to discuss the future of the eurozone with Chancellor Angela Merkel.
He will be the first Socialist leader since 1995 to occupy the Elysee Palace.
Francois Hollande will later try to “find a compromise” with Angela Merkel over the German-led focus on austerity as the way out of Europe’s economic crisis.
On Monday, the value of stock markets and the euro fell amid continuing political uncertainty in Greece.
The chairman of the eurozone finance ministers, Jean-Claude Juncker, insisted on Monday night that they would do “everything possible” to keep Greece in the euro.
Jean-Claude Juncker said he looked forward to the swift formation of a new Greek government, nine days after the general election.
But he also warned that Greece had to continue the “significant efforts” already made to restructure its economy despite these policies having been rejected by a majority of voters.
Francois Hollande is expected to be sworn in shortly after meeting outgoing President Nicolas Sarkozy at the Elysee Palace in central Paris at around 10:00.
The new leader has asked that the inauguration ceremony be kept as low-key as possible, and has invited just three dozen or so personal guests to join the 350 officials attending. Neither Francois Hollande’s children nor those of his partner, Valerie Trierweiler, will be there.
The ceremony will be followed by the traditional procession in an open-topped car along the Avenue des Champs-Elysees and the laying of the wreath at the Tomb of the Unknown Soldier underneath the Arc de Triomphe.
Francois Hollande will then pay tribute to the 19th-Century educational reformer Jules Ferry and the Nobel Prize-winning chemist Marie Curie.
His first lunch as president will be with the former Socialist prime ministers Pierre Mauroy, Laurent Fabius, Michel Rocard, Edith Cresson and Lionel Jospin.
Francois Hollande, 57, has spent the past week preparing to take up the presidency, and now the work begins in earnest.
His first job is to name a new prime minister, who our correspondent says will most likely be Jean-Marc Ayrault, leader of the Socialist group in parliament, a German speaker and a close ally.
Michel Sapin, a key economic adviser to Francois Hollande, is tipped to be finance minister.
On Tuesday afternoon, Francois Hollande will fly to Germany for dinner with Chancellor Angela Merkel, who says she will welcome the new leader “with open arms”.
But her embrace will hide some embarrassment after Angel Merkel openly supported Nicolas Sarkozy in the election battle.
“We don’t think the same on everything,” Francois Hollande acknowledged on French television on Monday.
“We’ll tell each other that so that together we can reach good compromises.”
Francois Hollande has demanded that a European fiscal pact that cracked down on overspending be renegotiated to include a greater emphasis on measures to stimulate growth, while Germany insists the treaty must be respected.
Whatever their differences, the crisis in the eurozone will put them under huge pressure to compromise, our correspondent says.
As the eurozone’s two biggest economies – and biggest contributors to its bailout funds – Germany and France are key decision-makers over the strategy supposed to pull Europe out of crisis.
According to official figures released on Tuesday morning, the French economy showed no growth in the first quarter of 2012. Growth in the final quarter of 2011 was also revised down to 0.1% from 0.2%.
However, Germany’s economy grew by a stronger than expected 0.5% in the first three months of the year.
Following his German trip, Francois Hollande will hold his first cabinet meeting on Thursday followed by a visit to Washington to meet US President Barack Obama on Friday.
• 08:00-08:30 Francois Hollande arrives at the Elysee Palace and meets Nicolas Sarkozy
• 08:30-09:30 Inauguration ceremony followed by procession up the Champs-Elysees
• 09:45 Francois Hollande lays a wreath at the Tomb of the Unknown Soldier, under the Arc de Triomphe
• 11:45 Francois Hollande pays tribute to Jules Ferry in the Jardin des Tuileries
• 12:30 Francois Hollande honours Marie Curie at the Curie Institute
• 13:00 Ceremony at the Hotel de Ville with Paris mayor Bertrand Delanoe