The 13-member panel recognised Lapeyre, 61, for his seventh book La vie est brève et le désir sans fin (Life is short and desire is endless). It is the story of two men in love with the same woman, viewed from one perspective, then the other.
Oksanen, 32, who has a Finnish father and an Estonian mother, won the foreign book award for her third novel, Puhdistus (Purge).
The first of her books translated into French, it is set during the retreat of Soviet troops from Estonia in 1992, telling the story of two women forced into prostitution.
It won the three top literary prizes in her native Finland, and in August it won the Roman Fnac prize, the first time the French prize was awarded to a foreign book. Oksanen will be the guest of honour at next year’s Paris book fair (18-21 March 2011).
Jean-Didier Vincent won the Prix Femina Essais non-fiction prize for his biography of the 19th century anarchist geographer, Elisée Reclus.
The Prix Femina was set up more than a century ago by a group of women who wanted a feminine version of the prestigious Prix Goncourt. The panel is made up of women, though the prize has been awarded to both men and women over the years.
The Goncourt prize is due to be announced on Monday.