Maddy \m(ad)-dy\ as a boy's name (also used as girl's name Maddy), is a variant of Madison. See for origin and meaning of Maddy.
The baby name Maddy sounds like Matty, Matt, Mathe, Mateo, Mata, Mat, Madteo, Matti, Mead, Meed and Meade. Other similar baby names are Laddy and Paddy.