A flame-retardant particle includes: a particle containing a compound having a structure represented by formula (1); and a coating particle that covers at least a part of a surface of the particle: -A(--O--CO--O--Ar).sub.m (1) wherein A represents a substituted or unsubstituted aromatic group; Ar represents a substituted or unsubstituted phenyl group; and m represents an integer of 1 to 3.