PROBLEM TO BE SOLVED: To provide an aqueous dispersion excellent in terms of adhesion and adhesiveness in relation to various substrates, etc. by avoiding the dispersion stability deterioration thereof even under severe conditions such as high temperatures, etc. and by inhibiting the attenuation of the film formability thereof on a coating occasion.SOLUTION: The provided aqueous dispersion is an aqueous dispersion obtained by dispersing, within an aqueous medium, a composite resin including a polyester resin (A) and a vinyl polymer (B) at a mass ratio of (A)/(B)=99/1-80/20 and the number-average molecular weight, acid value, and glass transition temperature of the polyester resin (A) are respectively 5000-50000, 3 mgKOH/g or more, and 30°C or less.