Ada may refer to—

1. A Jewish variant transliteration of Adah.
2. Ada, Lady Lovelace
3. Ada, sister of Charlemagne, for whom the Ada Gospels at Trier were produced.
4. Ada programming language
5. Ada, a genus of orchids
6. Places named Ada:
   • Ada, Saskatchewan , Canada
   • Ada, Nigeria
   • Ada, Serbia
   • Ada, Minnesota, United States
   • Ada, Ohio, United States
   • Ada, Oklahoma, United States
   • Ada Township, Michigan, United States
   • Ada Township, North Dakota, United States
   • Ada Township, South Dakota, United States
   • Ada County, Idaho, United States
7. As an initialism, ADA refers to
   • Aeronautical Development Agency of India's Ministry of Defence
   • Air Defense Artillery a branch of the United States Army
   • American Decency Association
   • American Dental Association
   • American Diabetes Association
   • American Dietetic Association
   • Americans For Democratic Action
   • Americans with Disabilities Act
   • Aotearoa Digital Arts
   • Assistant district attorney
   • Average Daily Attendance
8. The short title of Ada or Ardor: A Family Chronicle, a novel by Vladimir Nabokov (1969).