Type 1 diabetes (T1D) and celiac disease (CeD) are common autoimmune diseases in children where the pathophysiology is not fully characterized. The autoimmune process involves a complex scenario of both inflammatory and regulatory features. Galectin-1 (GAL-1) has a wide range of biological activities e.g., interaction with immune cells. We examined the relationship between GAL-1 and soluble immune markers and T cell subsets in a cohort of children with T1D and/or CeD relative to healthy children. Galectin-1, together with several soluble immune markers (e g interleukins (IL)), tumor necrosis factor (TNF), acute phase proteins and matrix metalloproteinases (MMP) were measured in sera from children with T1D and/or CeD by fluorochrome (Luminex) technique using children without these diseases as a reference. Subgroups of T cells, including T regulatory (Treg) cells, were analyzed by flow cytometry. Association between GAL-1, pro-inflammatory markers and Treg cells differed depending on which illness combination was present. In children with both T1D and CeD, GAL-1 correlated positively with pro-inflammatory markers (IL-1β, -6 and TNF-α). Composite scores increased the strength of correlation between GAL-1 and pro-inflammatory markers, Th1-associated interferon (IFN)-γ, and T1D-associated visfatin. Contrary, in children diagnosed with exclusively T1D, GAL-1 was positively correlated to CD25hi and CD25hiCD101+ Treg cells. For children with only CeD, no association between GAL-1 and other immune markers was observed. In conclusion, the association observed between GAL-1, soluble immune markers and Treg cells may indicate a role for GAL-1 in the pathophysiology of T1D and, to some extent, also in CeD.