Monsieur Forestier is a character from the short story "The Necklace" by Guy de Maupassant. He is a wealthy and successful man who plays a significant role in the life of the protagonist, Mathilde Loisel. Monsieur Forestier lends Mathilde a beautiful necklace for a high-society event, which becomes central to the story's plot. After losing the necklace, Mathilde and her husband face years of hardship to repay the debt incurred to replace it. Monsieur Forestier's character highlights themes of wealth, social status, and the consequences of pride in the narrative. His actions ultimately lead to a dramatic twist in Mathilde's life.