Sarkozy and other top UMP leaders have been marred by legal and financial scandals and are hoping for a new start as they gear up for the 2017 presidential race.
"'The Républicains' is not just a new name for a party. It's a rallying call to all who are distressed to see the Republic decline day after day and who want to stop this decline," Sarkozy said in a message on the party's new website republicains.fr.
Sarkozy, 59, returned to frontline politics last year and is expected to make a new bid for France’s top job in two years’ time.
He left the Elysée Palace in 2013 as one of France’s least popular presidents, and was immediately hounded by allegations related to campaign funding irregularities.
While his much-heralded comeback has been slowed by the accusations swirling around him and other party figures, Sarkozy’s party gave the ruling Socialists a drubbing in local elections last month.
It was nevertheless unclear if the new name would help Sarkozy and the UMP turn a new leaf.
Just 46 percent of UMP members took part in the online vote to rename the party, and many non-affiliated voters in France have expressed indignation at the move.
A party congress will take place in Paris on Saturday, with Sarkozy set to give the closing speech.