诉诸群众（拉丁语：Argumentum ad populum）是一种逻辑谬误、一种社会心理的状态、也是一种宣传的技巧，常被称为「从众」，代表人类害怕在社会中被孤立，因而向社会其他多数靠拢的一种过程。

诉诸群众尚有许多称呼，如诉诸多数（appeal to the majority）、诉诸大数（Argumentum ad numerum）、诉诸民主（appeal to the democracy）、诉诸信念（appeal to belief）、共识谬误（consensus fallacy）、乐队花车谬误（bandwagon fallacy）等等。

In argumentation theory, an argumentum ad populum (Latin for "appeal to the people") is a fallacious argument that concludes that a proposition is true because many or most people believe it: "If many believe so, it is so."

This type of argument is known by several names, including appeal to the masses, appeal to belief, appeal to the majority, appeal to democracy, appeal to popularity, argument by consensus, consensus fallacy, authority of the many, and bandwagon fallacy (also known as a vox populi), and in Latin as argumentum ad numerum ("appeal to the number"), and consensus gentium ("agreement of the clans"). It is also the basis of a number of social phenomena, including communal reinforcement and the bandwagon effect. The Chinese proverb "three men make a tiger" concerns the same idea.