The ACT (originally abbreviation of American College Testing) is a standardized test for high school achievement and college admissions in the United States produced by ACT, Inc.It was first administered in fall 1959 by Everett Franklin Lindquist as a competitor to the College Board's Scholastic Aptitude Test, now the SAT Reasoning Test. Some students who perform poorly on the SAT find that they perform better on the ACT and vice versa.[3] The ACT test has historically consisted of four tests: English, Math, Reading, and Science reasoning. In February 2005, an optional writing test was added to the ACT, mirroring changes to the SAT that took place later in March of the same year. All four-year colleges and universities in the U.S. accept the ACT, but different institutions place different emphases on standardized tests such as the ACT, compared to other factors of evaluation such as class rank, G.P.A., and extracurricular activities.

In 2005 the company established ACT International. This organization is composed of ACT Education Solutions, Limited, and ACT Business Solutions, B.V. ACT Education Solutions is directed toward helping non-native speakers learn English in preparation for studying at an English-speaking educational institution. ACT Business Solutions attempts to help employers assess their employees' level of English proficiency through use of the WorkKeys assessment.