Alexithymia, a difficulty identifying and expressing emotions experienced by oneself or others, measurably harms quality of sleep. Research has observed the association between alexithymia and sleep problems; however, the cumulative effect of this association is still unknown. Therefore, this systematic review and meta-analysis was conducted to present scientific evidence regarding the relationship between alexithymia and sleep quality. Adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline, and using relevant keywords, we searched six databases: Scopus, PubMed Central, ProQuest, ISI Web of Knowledge, EMBASE, and Science Direct. We selected observational studies on the association between alexithymia and sleep. We conducted meta-analysis using a random-effect model to calculate the effect size (ES) with Fisher's z transformation. Eligible studies (N = 26) in 24 papers included 7546 participants from 12 countries. The entire ES for the association between alexithymia and sleep was 0.44 (95 % CI: 0.31, 0.56). Additionally, patient populations had a larger ES (ES = 0.55; 95 % CI: 0.30, 0.79) than healthy populations (ES = 0.30; 95 % CI: 0.20, 0.41). The results of the present systematic review and meta-analysis revealed a significant association between alexithymia and sleep problems, especially among people with any medical condition.