Article II, Section 1, Clause 5:

No Person except a natural born Citizen, or a Citizen of the United States, at the time of the Adoption of this Constitution, shall be eligible to the Office of President; neither shall any Person be eligible to that Office who shall not have attained to the Age of thirty five Years, and been fourteen Years a Resident within the United States.

The Qualifications Clause set forth in Article II, Section 1, Clause 5 requires the President to be a natural-born citizen, at least thirty-five years of age, and a resident of the United States for at least fourteen years.1

Like the age requirements for membership in the House of Representatives2 and the Senate,3 the age requirement for the presidency set forth at Article II, Section 1, Clause 5 ensures that persons holding the office of President will have the necessary maturity for the position as well as sufficient time in a public role for the electorate to be able to assess the merits of a presidential candidate.4 In his Commentaries on the Constitution of the United States, Justice Joseph Story stated: Considering the nature of the duties, the extent of the information, and the solid wisdom and experience required in the executive department, no one can reasonably doubt the propriety of some qualification of age.5

The Framers appear to have adopted the requirement that citizens be natural born citizens to ensure that the President’s loyalties would lie strictly with the United States. By barring naturalized citizens from the presidency, the requirement of being a natural born citizen, as Justice Story explained, protects the United States from ambitious foreigners, who might otherwise be intriguing for the office; and interposes a barrier against those corrupt interferences of foreign governments in executive elections, which have inflicted the most serious evils upon the elected monarchies of Europe.  https://constitution.congress.gov/browse/essay/artII-S1-C5-1/ALDE_00013692/ 6