Yes, negative 3 is a rational number. A rational number is defined as any number that can be expressed as the quotient of two integers, where the denominator is not zero.
In the case of negative 3, it can be expressed as -3/1. Here, -3 is the numerator (an integer) and 1 is the denominator (also an integer and not zero). Since it meets the criteria for being a rational number, we can confidently say that negative 3 is indeed rational.