Alcetas I of Macedon (Greek: Ἀλκέτας ὁ Μακεδών; 576–547 BC) was a son of Aeropus I of Macedon and the 8th king of Μacedon, counting from Karanus, and the 5th, counting from Perdiccas, reigning, according to Eusebius, 29 years. He was the father of Amyntas I, who reigned in the latter part of the 6th century BC.
By all accounts, Alcetas was a calm and stable ruler, who sought to preserve his kingdom through peaceful means. Unlike his predecessors, he apparently did not engage in unnecessary warfare in order to extend the boundaries of his kingdom. His wife is unknown.