Is there an age limit for entering colleges and universities in the United States to become a college teacher?

Yes.

There are age restrictions for university recruitment of teachers: Applicants for lecturer positions are generally not more than 35 years old, and applicants for associate professor positions and above are generally not more than 45 years old. In principle, the recruitment of teachers in colleges and universities should have a doctoral degree or the highest degree in the subject.

Teacher Recruitment Examination Application Requirements: Aged 35 and below, obtain a teacher qualification certificate consistent with the position applied for, college degree or above, obtain corresponding academic qualifications and degree certificates; be in good health and be able to adapt to daily teaching Requirements; having the nationality of the People's Republic of China, abiding by the Constitution and laws, and having good conduct and professional ethics.