The main purposes of this study were: to profile the usage of, and confidence in, social media as study sources among undergraduate students for academic purposes and to compare the level of usage of, and confidence in, social media with other study sources. A cross-sectional survey about educational sources and social media usage and confidence, composed of eight items with closed-end-type Likert scale responses (1 to 5 points), was answered by 406 Brazilian physical education undergraduate students (236 men and 170 women) recruited from two public universities. Of these students, 98.3% used social media. Social media (median: 3), books (median: 4), scientific articles in Portuguese (median: 4) and blogs/websites (median: 4) obtained similar usage scores (p > 0.05) but higher (p < 0.05) than other study sources. Books (median: 5) and scientific articles (median: 5) obtained a similar confidence score (p > 0.05) but higher (p < 0.05) than social media. Social media presented widespread usage as study sources despite the lower level of confidence attributed to them.