The organ responsible for producing testosterone in males is the testes. These reproductive glands play a pivotal role in the male endocrine system, producing hormones essential for the development of male secondary sexual characteristics, such as facial hair and deeper voice. Testosterone also influences various bodily functions, including muscle mass, bone density, and libido. The regulation of testosterone production is influenced by signals from the hypothalamus and pituitary gland, ensuring proper hormonal balance throughout a male's life.