Ida or IDA may refer to:

• Ida (given name), including people so named
• Ida (surname), a list of people so named

Ila or Ila is an androgyne in Hindu mythology, known for their sex changes. As a man, he is known as Ila or Sudyumna and as a woman, is called Ila. Ila is considered the chief progenitor of the Lunar dynasty of Indian kings - also known as the Ailas ("descendants of Ila").

Iterative deepening A* (IDA*) is a graph traversal and path search algorithm that can find the shortest path between a designated start node and any member of a set of goal nodes in a weighted graph. It is a variant of iterative deepening depth-first search that borrows the idea to use a heuristic function to evaluate the remaining cost to get to the goal from the A* search algorithm. Since it is a depth-first search algorithm, its memory usage is lower than in A*, but unlike ordinary iterative deepening search, it concentrates on exploring the most promising nodes and thus doesn't go to the same depth everywhere in the search tree. Unlike A*, IDA* doesn't utilize dynamic programming and therefore often ends up exploring the same nodes many times.