Is the Golgi apparatus involved in secretion?

Yes, along with the endoplasmic reticulum (ER) and transport vesicles, the Golgi apparatus is part of the secretory pathway. It is this pathway that cells use to secrete proteins into their extracellular environment. Proteins synthesized by the rough ER are delivered to the Golgi apparatus via transport vesicles. As proteins traverse the Golgi they are biochemically modified, repackaged into transport vesicles and transported to the cell surface for secretion.