Ada Mercedes Maza (born September 17, 1958, in La Rioja) is an Argentine Justicialist Party politician. She sit in the Argentine Senate representing La Rioja Province in the majority block of the Front for Victory. On October 14, 2001, Maza was elected as a Senator. She was re-elected in 2005, taking the place of her brother Ángel Maza, who did not take his seat but continued as governor of La Rioja. Previously close to former President and fellow La Rioja Senator Carlos Menem, she is now in the ranks of followers of Kirchnerism.