* Exceptional talent or achievement: A student with demonstrable skill in a specific area might be admitted, even without a high school diploma. This is rare and usually applies to exceptionally gifted individuals.
* Successful completion of a college preparatory program: Some programs specifically prepare students who lack a high school diploma for college-level work. Successful completion of such a program might lead to admission.
* Demonstration of college readiness through alternative testing and portfolios: A student might demonstrate readiness through alternative assessments, showcasing a level of knowledge and skills equivalent to a high school diploma. This is also uncommon.
In short, while technically possible, it's highly improbable. Obtaining a GED or equivalent is a far more realistic and advisable path to college admission for those lacking a high school diploma.