Prelude The curtain opens to reveal an otherwise empty fin-de-siècle ballet studio. In the early morning light, everything is ready to commence the daily practice session. Amor – rejoicing at finally being able to move around freely – is glimpsed descending from his perch amongst the clouds on the painted ceiling fresco to the floor, where he begins a merry dance. In the meantime, the door to the room opens to admit Sylvia, the diligent soloist, who has arrived early to warm up before everyone else arrives. Amor hides. Orion, the company's director and ballet master also arrives. This is no coincidence: he is enamoured of the ballerina. His technical instructions make it evident that the "help" he is providing involves something more than the usual relationship between colleagues. Orion's advances become more ardent, but Sylvia objects and fends them off. Witnessing all this from his hiding place, Amor leaps out just in time and, as a fellow member of the company, greets them. Then the young male soloist Amyntas comes in, and scarcely able to conceal his emotions, self-consciously greets Sylvia, whom he's in love with. Orion, who has seen everything and is naturally aware of the situation between the two, gives his "rival" a brief but nasty stare. After a short practice session, everyone departs, leaving only the seething Orion in the room.
Scene 1 Now the work begins in earnest. Everyone enters and takes his or her usual position alongside the barre, where they commence the compulsory daily exercises. At the end of the session, the fatigued dancers take a break. The action on stage seems to almost freeze as attention focuses on Amyntas, whose expressed thoughts reveal his love for Sylvia. A horn sounds from the distance to signal the arrival of Diana, the company's pampered and adulated star, who also happens to be the director's wife. Diana, grandly dressed in a style befitting a "diva", bursts into the room. Orion, with his displeasure compounded by the star's tardiness, irately watches her perform her dance, which his wife concludes by falling into his arms. Orion pushes her off. The offended Diana reacts by grabbing Amyntas and pulling him towards her. In response to this, Orion grabs Sylvia for a dance. Amor also joins the quartet. Emotions gradually cool, and finally the rehearsal for the ballet performance is ready to begin.
Scene 2 The dance company starts to rehearse the ballet's well-known waltz. In the meantime, the scene changes: the ballerinas in their practice clothes are replaced by costumed dancers. The setting also shifts to that of the "actual" ballet: the statue of Amor rises in the sacred wood, and nymphs dance around it in the moonlight. After the waltz ends, a centaur appears and after casting a meaningful glance at Sylvia and Diana, starts to dance with them. Eventually he chooses Diana as his favourite of the two and carries her off. Sylvia, on the other hand, sights the spying shepherd lad Amyntas. The nymphs seize him, and Sylvia shoots an arrow at him. The injured Amyntas collapses. Amor then comes to life and also shoots an arrow, this time at Sylvia, who now wounded, clutches her heart and is led from the wood by her anxious companions. Amyntas, suffering from his injury, is left alone at the base of the statue. Orion appears in the form of a satyr and glimpses Sylvia, who out of remorse has returned to the shepherd boy. Orion hides in the shrubbery. Sylvia, now in love with Amyntas due to the effects of Amor's arrow, is about to give him aid, but Orion jumps out from his hiding place and abducts the girl he has long desired. Powerless and still injured, Amyntas prays for assistance from the god of love, prompting Amor to descend from his pedestal in order to heal his wound, and together the two head off to find the abducted Sylvia.
Scene 3 The scene returns to the ballet studio. Amor is sitting on his pedestal in a state of boredom. He finds himself obstructing the way of a man and woman from the costume department, but this causes him no concern. Putting on a ballet shoe that has been left there, he abandons himself in a mirthful dance. Before vanishing from the scene, he also manages to – accidentally – wound the two dressers with arrows, causing them to fall in love with each other as well. The door opens. Orion enters with Sylvia, whom he has brought into his "cavern" as his booty. After closing the door for the sake of safety, he begins to besiege – through dance – the protesting Sylvia (with the set meanwhile changing to a cave). He nearly achieves his aim: the girl is already in his arms when after a great commotion the door bursts in on them. Amyntas, Amor and Diana enter to find them in their thoroughly compromising position. The entire dance company spills out after them, watching at first in confusion, later with ill-concealed malice, as Diana demands an explanation. The crestfallen Amyntas contemplates Sylvia in despair. Orion's attempts to explain himself do him little good. The humiliated Sylvia departs in tears of shame, followed by Amor. Overcome by despair, Amyntas faints into the arms of his colleagues.
Scene 1 In the ballet studio, the lonesome Amyntas is busy practising. Diana enters and attempts to approach the youth. Amyntas at first rejects the advances, but his resistance gradually dwindles, and in a trance-like state, he kisses Diana. Nevertheless, he suddenly realises his infidelity and rejects the kiss. Diana accepts this turn of events with typical feminine empathy and departs. Amyntas, on the other hand, is again left in loneliness and despair as he thinks of Sylvia.
Scene 2 An enormous galleon appears on the stage, bearing Amor and Sylvia: the god has brought her to her beloved.
Scene 3 The setting changes again to Diana's wood, where a sacrificial ceremony is underway, with Diana herself presiding, accompanied by her priestesses. The scene is interrupted as the lovers flee before the wrathful Orion, who pursues them, claiming Sylvia as his own. With a shot from her bow, Diana then mortally wounds Orion in his guise as a satyr. Amyntas and Sylvia are then able to join together without hindrance.
Scene 4 The members of the ballet company assemble in the now festively decorated ballet studio for Sylvia and Amyntas's wedding. Now dressed in "regular" clothes, they all cheerfully toast the young couple. Orion comes in to congratulate them and also takes a place at the table of honour. Amyntas expresses his feelings with a solo dance that also displays his keen understanding of the events. His dance is followed by another solo dance by Sylvia. At the request of the newlyweds, the esteemed master Orion also performs. The increasingly good spirits inspire the entire wedding party to join in. The fine mood is disrupted by Diana's "bursting in" – in the same way she did at the beginning of the performance – to display her injured pride. Her seething anger completely ruins the fun. She quarrels with Sylvia, thrusts Amyntas aside, and then explodes into sobbing as she makes ready to depart. The members of the company attempt to detain her – without much success – until Amor intervenes once again, shooting an arrow at Diana, who melts lovingly into Orion's arms. Now everyone is happy. Especially Amor, who with his work now finished, returns to his former position up high and contentedly observes the whirling merriment below.