King Ferdinand of Navarre is a ruler whose decision to make 'a little academe' (1.1.13) of his court leads to the action of the play. Although opposed by the sardonic humor of BEROWNE, the King bans all mirth, banqueting, and even the company of women in order to promote disinterested study. The King's humorless desire to make of his courtiers 'brave conquerors . . . / That war against your own affections / And the huge army of the world's desires' (1.1.8-10) is focused on an abstract idea, not a love of scholarship, and is therefore vain. This self-centered seriousness is overcome by love as the play develops. The King himself succumbs to the charms of the Princess of France, and when, at the close of the play, she requires that he prove his love with a year of monastic life, he willingly assumes the task, asserting, 'My heart is in thy breast' (5.2.808).

Berowne's name, pronounced 'B'roon', is taken from that of a contemporary French Protestant general, the Due de Biron, who was a principal adviser to the historical King of Navarre.

Longaville's name was taken from that of a French contemporary of Shakespeare, the Due de Longueville, a well-known figure in the Wars of Religion.  Longueville was an aide to Henri de Bourbon, who was the historical King of Navarre and later ruled France as Henri IV.

Dumaine (Dumain) is one of the gentlemen who fall in love and thus disrupt the ascetic academic program of the King of Navarre. Although committed to the King's idea at the outset of the play, Dumaine falls in love with Katharine, a lady-in-waiting of the Princess of France. Along with the King and the other courtiers, he breaks his vows and abandons scholarship for love.  The Due de Mayenne, well known in Shakespeare's London for his role in the French Wars of Religion, is usually thought to have provided the name Dumaine.  Unlike the originals of Longaville and Berowne, he was not an aide to the historical King of Navarre; rather, he was a principal enemy of the insurgent monarch, but this inconsistency would probably not have bothered either the playwright or his audience. An alternative, the less notable General D'Aumont, who was an aide to the King of Navarre at the time, has been proposed.

Boyet Minor is in the entourage of the Princess of France.  Boyet is a smooth courtier, a familiar type in the Elizabethan court. We first see him flattering his mistress and being put in his place. He often serves as a messenger. He happens to overhear the plans of the King and his gentlemen to masquerade as Russians, and he warns the Princess and her ladies. Berowne expresses his dislike for Boyet in 5.2.315-327

Marcade (Mercade) is the messenger who brings the news to the Princess of France news of her father's death in 5.2, thus changing the tenor of the play in its closing minutes.

Armado boasts of his acquaintance with the King of Navarre in a richly comical passage (5.1.87-108) and clearly demonstrates his descent from the comic character type known in ancient Roman drama as the Miles Gloriosus, a foolish, bragging soldier. In the Italian Commedia Dell’Arte, this figure was a Spaniard, an enemy of Italy and also of Shakespeare's England. Armado's very name, attached to so ludicrous a character, is a derisive reference to the Spanish Armada's grand failure to invade England in 1588.

Nathaniel is the obsequious companion of the comical pedant Holofernes. Nathaniel emulates his friend, seconding his opinions with less Latinity but no less pretension. Although Nathaniel is no more than an object of derision for the most part, Costard presents him in a more human light, standing up for him in 5.2, when he has at the pageant, stricken with stage fright.

While Shakespeare's audiences will have made more of Holofernes' ranting than we can, it is nonetheless good comedy, for much of the fun lies in its near-incomprehensibility. Some of his references are clearly to topical jokes that are now hopelessly obscure. It has been speculated that Holofernes was intended as a parody of some contemporary literary figure—John Florio and Gabriel Harvey have been suggested—but this theory cannot be proven.

Dull is the slow-witted rustic constable. Dull is a character type whose name summarizes his nature. Dull acts as a foil to the comical pedants Armado, Holofernes, and Nathaniel, offsetting their elaborate contortions of language by being himself. At one point, Holofemes observes, 'Via, goodman Dull! Thou hast spoken no word all this while'. Dull replies, 'Nor understand none neither, sir' (5.1.141).

Costard is a quickwitted Clown who is at the centre of the rustic sub-plot. In 3.1 Costard is employed by Armado to send a love letter to Jaquenetta and by Berowne to send another one to Rosaline. He delivers each to the wrong woman, resulting in two comical outcomes:  Armado's pompous rhetoric is read aloud to the amusement of the Princess of France and her retinue; and Berowne's love poem exposes to his fellow courtiers his own susceptibility to romance, just as he is chastising them for the same failing.  To a great degree. Costard is simply a character type derived from the Italian Commedia Dell’Arte tradition—that of the servant or rustic yokel descended from the comic slave figures of ancient Roman Drama. He engages in several bits of standard by play—for instance, when he comes to believe that 'remuneration' means a three-farthing coin and 'guerdon' a shilling. However, he displays realistic touches of humanity that rank among the play's literary gems.  A participant in the comical pageant of the Nine Worthies, Costard plays Pompey the Great, but he muffs his lines and shamefacedly apologizes, in 5.2.554-555. Some twenty lines later, Costard demonstrates an appreciation for his fellows that exceeds the restricted humanity of a stock figure, when he speaks up for Nathaniel the Curate, who has been driven away by stage fright. Costard's name is an old word meaning 'apple' or 'head', which stimulates a cluster of jokes in 3.1.

Moth is a page employed by the Spanish braggart Armado.  Moth's quick wit is employed to ridicule his master, subtly to his face and blatantly behind his back. Moth appears only in scenes that function as set pieces, humorous sketches intended simply as entertainment.  Moth is apparently an energetic teenager or child, small and slight of build. He is described as 'not so long by the head as hononficabilitudinitatibus' (5.1.39- 40) (the longest word in Latin, and in Shakespeare).  His name, pronounced 'mote' in Elizabethan English, suggests both the erratic flight of an insect and the elusiveness of a particle of dust. In the pageant of the Nine Worthies (5.2), he plays the infant Hercules. He is the vehicle for a number of the obscure topical jokes that make Love's Labour's Lost the most cryptic of Shakespeare's plays. He is believed to have been in tended as a parody of the peppery Elizabethan pamphleteer and satirist Thomas Nashe.

Forester is the guide for a royal hunt. The Forester's naive honesty : provides a foil for the wit of the Princess of France in 4.1.

The Princess is the head of an embassy from France to the court of the King of Navarre, who falls in love with her.  When we first encounter the Princess, in 2.1, she reprimands her courtier, Boyet, for his flattery in sharp but sensible terms that immediately establish her as a straightforward woman. But, although we do have a sense of the Princess as a real person, her chief role in the play is as a participant in the courtly tableau of lovers that draws the King and his gentlemen to an awareness that their narrow world of asceticism is insufficient compared to the power of love.  In 5.2, when she learns of her father's death, the Princess prepares to leave Navarre immediately. She responds to the King's suit by requiring him to live as a hermit for a year to test the strength of his love. She recognizes that the process of maturation that the gentlemen have undergone in the course of the play is not complete—a recognition that makes her the character who perhaps most clearly represents the play's point of view.

Described as having a strikingly dark complexion, and demonstrating a provoking wit, Rosaline is presumed to have been linked, in Shakespeare's mind, to the Dark Lady of the Sonnets, although this cannot be proved. She does seem to anticipate later Shakespearean heroines who are plainly among his favorite types—attractive and assertive young women such as Beatrice, Portia, and her near Rosalind. 

Maria is the beloved of Longaville and one of the ladies-in-waiting to the Princess of France. Maria, like her lover, functions simply as a figure in the courtly pageant of love that constitutes the play's main plot. She has no distinctive personality traits, although she may be said to anticipate more fully developed secondary female characters, such as Nerissa, in The Merchant of Venice.

Katharine (Katherine; Catherine) is  the beloved of Dumaine and a lady-in-waiting to the Princess of France. Although primarily a stock figure in the play's courtly tableau of lovers, she is given a flash of true human feeling. In 5.2, Rosaline teases her about a sister who was said to have died of love, and Katharine is overtaken by her memory of the occasion. 'He made her melancholy, sad, and heavy; / And so she died: had she been light, like you, / Of such a merry, nimble, stirring spirit, /She might ha' been a grandam ere she died.'(5.2.14-17). This brief remark gives us not only a glimpse of a young woman's recollected grief, but we receive an impression of Rosaline's character as well.  It is thought that Shakespeare derived the story of Katharine's sister's death from a current account of a similar demise among the attendants of the historical Princess of France of the day. Marguerite of Valois, who was in fact married to the King of Navarre. The same tale may also have influenced the Ophelia episode in Hamlet.