Although researchers have investigated the effects automated writing evaluation (AWE) and teacher corrective feedback have on second language (L2) writing performance, these studies have conflated two different variables—feedback source and perceptions of feedback source. Using a quasi-experimental design, two groups of second language English writers—perceived teacher feedback group (N = 88) and perceived automated feedback group (N = 73)—received feedback on four essays written over an 18-week academic semester. While both groups received AWE and a marked rubric as feedback, the perceived teacher feedback group was under the impression that the AWE was given by their teacher. Results showed the perceived automated feedback group outperformed the perceived teacher feedback group on essay 2 and essay 3; however, the reverse was found for essay 4. Furthermore, the perceived automated feedback group showed statistically significant differences in writing performance; they improved from essay 2 to essay 3 but regressed from essay 3 to essay 4. Perceptions of the feedback source may have caused these results, suggesting that it should be worthwhile to inform L2 student writers of the feedback source. Before providing feedback to L2 student writers, teachers can inform students on how their writing performance can benefit from AWE and afterwards the teachers can meet students’ needs by following up with the delivery of teacher feedback.