DDO may refer to:
== Science and technology == David Dunlap Observatory Catalogue, a catalogue of dwarf galaxies that was published in 1959 DDO (gene), that encodes the D-aspartate oxidase enzyme Distant detached objects, class of minor planets in the outer reaches of the Solar System Dynamic Drive Overlay, a software technique to extend a system BIOS
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).