{infobox graph

| name = Complete graph
| image = 
| image_caption = , a complete graph with 7 vertices
| vertices = 
| radius = 
| diameter = 
| girth = 
| edges = 
|notation = 
| automorphisms    = 
| chromatic_number = 
| chromatic_index =  if  is odd
 if  is even
| spectrum = 
| properties = 
Symmetric graph
Vertex-transitive
Edge-transitive
Strongly regular
Integral  

}} In the mathematical field of graph theory, a complete graph is a simple undirected graph in which every pair of distinct vertices is connected by a unique edge. A complete digraph is a directed graph in which every pair of distinct vertices is connected by a pair of unique edges (one in each direction).