Education reform efforts, including the current adoption of Common Core State Standards, have increased attention to teaching critical thinking skills to all students. This study investigated the critical thinking skills of fourth-grade students from a school district in Texas, including 45 identified gifted students and 163 general education students. Identified gifted students outperformed general education students on both the Cornell Critical Thinking Test and the Test of Critical Thinking ("d" = 1.52 and "d" = 1.36, respectively). There was no evidence of main effects or interaction effects for gender in measures of critical thinking within these samples. Critical thinking scores of students in the three schools did not differ significantly, nor were differences in scores associated with length of exposure to the gifted education program. The association of higher ability with advanced critical thinking skills, but at the same time, the lack of evidence of an effect of the gifted education programs (which did not focus specifically on critical thinking skills) suggests that differentiation of curriculum and instruction for gifted or advanced learners might fruitfully include deliberate differentiation of instruction in this area.