The Secrets Cave: Discovering Lascaux by Emily Arnold McCully

From chapters.ca:
Jacques, Jojo, Simon, and Marcel were looking for buried treasure when they explored a cave in the south of France in 1940. But the treasure inside was not what they expected, and in fact far more valuable: the walls were covered with stunning prehistoric paintings and engravings, preserved within the sealed cave for over 17,000 years. This is the true story of the boys who discovered the cave of Lascaux, bringing to the modern world powerful examples of the very beginning of art.

Everybody Bonjours! By Leslie Kimmelman, illustrated by Sarah McMenemy

From chapters.ca:
Shop a fancy France-y store. Eat a pretty petit four. Discover! Sightsee! Explore! On this fun and friendly tour, everybody says "Bonjour!" Whether at a soccer stadium, a crêpe stand, or strolling the Champs d'Elysee, a little girl and her family are welcomed everywhere with the signature French greeting. Jump into these pages and enjoy the trip! Through lilting words and lively images, Everybody Bonjours welcomes young reader- travelers to a Paris that isn't just for artists, grown- ups, and dreamers - it's for kids!

Madeline and the Cats of Rome by John Bemelmans Marchiano

From chapters.ca:
The Paris skies are grey, so Miss Clavel and the twelve little girls are leaving for brighter weather - spring in Rome. Rome has wonderful sights to see and delicious things to eat, but Madeline also finds an unexpected adventure, involving a thief, a chase, and many, many cats. The first all- new Madeline book in close to fifty years combines a lively story with luminous watercolour illustrations. Beloved Madeline returns, as brave and irrepressible as ever.

LionBoy by Zizou Corder

From chapters.ca:
One day in the near- future world, Charlie Ashanti's parents make a dramatic discovery - the cure for asthma. Then they disappear, kidnapped! Ten- year- old Charlie makes a swift decision: he will search far and wide until he finds them. Relying on a unique talent - the ability to speak Cat (gained when he was scratched by a leopard as a baby) - Charlie communicates first with the cats of London and then with the lions in a Paris circus to look for and communicate with his parents....Lionboy is a gripping tale packed with evil villains, brave heroes, and surprising plot twists. A story that intrigues and exhilarates - destined to become a classic.

Madame la Grande and Her so High to the Sky Uprorious Pompadour by Candace Fleming, illustrated by S. D. Schindler

Madame la Grande likes to follow all the fashions in her native Paris, but she is not very good at it. When the pompadour comes into style she just has to have one, but, as usual, she doesn't quite get it right.

The Red Balloon by A. Lamorisse

From the publisher:
A magical book that has become an enduring children's classic, The Red Balloon is the story of a young boy and his best friend--a bright red balloon. Chock-full of photographs of the boy, the balloon and the captivating city of Paris.

The Lady with a Ship on Her Head

Lady Pompenstance wants to win the award for best hairstyle at the ball, but she cannot think of anything. While she is walking along the shore, a very small sailing ship sails into her hair, but she does not notice.

Les Miserables by Victor Hugo

From chapters.ca:
Few novels ever swept the world with such overpowering impact as "Les Miserables". Sensational, dramatic, packed with rich excitement and filled with the sweep and violence of human passions, "Les Miserables" is not only a superb adventure but a powerful social document. The story of how the convict Jean Valjean struggles to escape his past and reaffirm his humanity in a world brutalized by poverty and ignorance became the gospel of the poor and oppressed.

The Scarlet Pimpernel by Baroness Orczy

From chapters.ca:
One of the most famous swashbucklers ever, The Scarlet Pimpernel recounts in classic good-versus-evil style foppish English nobleman Sir Percy Blackeney's daring rescues of French aristocrats from the clutches of Madame Guillotine, mistress of the Reign of Terror.

The Count of Monte Cristo by Alexandre Dumas

From chapters.ca:
Falsely accused during the final days of Napoleon's reign, Edmond Dantès is imprisoned in the bleak Chateau d'If. After a hair-raising escape, he launches an elaborate plot to extract a bitter revenge against those who betrayed him.

Amazingly, this book is apparently based on true events.
As the original is over 1000 pages, I recommend an abridged version for younger or less patient readers.

Madeline by Ludwig Bemelmans

Another classic picture book that has stood the test of time. Madeline lives in an orphanage in Paris with 11 other little girls and they have a number of adventures together.

The Three Musketeers by Alexandre Dumas

The three musketeers, Aramis, Athos, Porthos, and the not-quite-yet Musketeer D’Artagnan must work to save France from treasonous plots. A great story with tons of adventure and romance.

Cyrano de Bergerac by Edmond Rostand

Cyrano has a quick sword and an equally quick wit. Unfortunately for him, he also has an enormous nose. Set in the France of Louis XIII, the play follows his courtship of Roxane.

If you can read it in the original French, do.

Monsieur Saguette and His Baguette by Frank Asch

Monsieur Saguette goes out to buy a baguette to have with his meal. On the way, his bread turns out to be extremely handy.