The age of consent is 17.
The age of majority is 18 (legal adult)

Missouri Revised Statutes
Chapter 566
Sexual Offenses Section 566.034

566.034 Statutory rape, second degree, penalty.

1. A person commits the crime of statutory rape in the second degree if being twenty-one years of age or older, he has sexual intercourse with another person who is less than seventeen years of age.

2. Statutory rape in the second degree is a class C felony.

566.032 Statutory rape, first degree, penalties.

1. A person commits the crime of statutory rape in the first degree if he has sexual intercourse with another person who is less than fourteen years old.

2. Statutory rape in the first degree is a felony for which the authorized term of imprisonment is life imprisonment or a term of years not less than five years, unless in the course thereof the actor inflicts serious physical injury on any person, displays a deadly weapon or dangerous instrument in a threatening manner, subjects the victim to sexual intercourse or deviate sexual intercourse with more than one person, or the victim is less than twelve years of age in which case the authorized term of imprisonment is life imprisonment or a term of years not less than ten years.

207.69.137.21