Completion may refer to:

• Completion (American football)
• Completion (oil and gas wells)
• Completion, a 2004 studio album by Bodychoke
• One of the landmarks in conveyancing, transfer of the title of property from one person to another

• Completion (metric space), constructing the smallest complete metric space containing a given space
• Construction of a complete measure space
• Dedekind–MacNeille completion, constructing the smallest complete lattice containing a given partial order
• Completion (algebra)
• completions in category theory

• Autocomplete, predicting a phrase the user is about to type in
• Knuth–Bendix completion algorithm, transforming an equation set into a confluent term rewriting system

• Completeness (disambiguation)