The Blue Lions house at the Officers Academy is comprised of students who hail from the Holy Kingdom of Faerghus. As their homeland is known for its knights, many of the students are proficient at using spears.
The Blue Lions were named after the founder of Faerghus, Loog, the King of Lions, who had a penchant for blue.
- Dimitri Alexandre Blaiddyd - The noble Prince of the Holy Kingdom of Faerghus and the house leader of the Blue Lions. Has a tinge of darkness beneath his chivalrous demeanor.
- Dedue Molinaro - A man from Duscur who was spared from his people's genocide by Dimitri. Owes him a life debt and is his most faithful servant.
- Annette Fantine Dominic - The intelligent yet absent minded estranged daughter of Gilbert and heir of House Dominic. Inheritor of the magical axe Crusher
- Ashe Ubert - A former thief adopted by Lord Lonato. Aspires to be a knight like his adoptive older brother.
- Mercedes von Martritz - The adopted daughter of a merchant family with a gentle, easygoing personality. Holder of the Crest of Lamine.
- Sylvain Jose Gautier - The skirt chasing heir of house Gautier and sole holder of its crest. Inheritor to the Lance of Ruin.
- Felix Hugo Fraldarius - The sharp-tongued son of house Fraldarius who challenges any person he deems strong to a duel. Inheritor of the Aegis Shield
- Ingrid Brandl Galatea - The knightly and chivalrous heir of house Galatea and holder of the Crest of Daphnel. Inheritor of the lance Lúin.
The Japanese pronunciation of the three classes take their names from German. The Blue Lions are roughly called "Löwenklasse," which means "Lion Class."
- The Blue Lions is the only house that has an unequal distribution of male and female members.
- The Blue Lions path (Azure Moon) is the route where the most playable characters can survive.
- In a survey conducted by Nintendo DREAM Magazine, the Blue Lions ranked 1st among the houses chosen in Fire Emblem: Three Houses. The male-female vote ratio was 1:2. It received 42.6% of the vote.