Just before 10 p.m. on Sunday, police were called to a section of the park near the Conservatory of Flowers.
Police found the body of 25-year-old man near Conservatory Drive and John F. Kennedy Drive. He had been stabbed during a confrontation.
Police took a man in his 60s into custody after he flagged down a passer-by and asked to call police and they are still investigating what led up to the violence and looking for witnesses.