Type 2 diabetes mellitus (T2DM) incidence is increasing worldwide. The fatty acid composition of phospholipids—a major component of biological membranes—has received research attention owing to their involvement in T2DM onset and progression. We hypothesized that changes in the fatty acid composition of phospholipids in the liver, the central organ of energy metabolism, alleviate their aberrant metabolism. We focused on lysophospholipid acyltransferase 10 (LPLAT10/LPCAT4/LPEAT2), an enzyme that changes the fatty acid composition of phospholipids, and examined the effect of LPLAT10 on glucose metabolism. To overexpress LPLAT10 in mouse liver, we generated an LPLAT10-expressing adenovirus (Ad) vector (Ad-LPLAT10) using an improved Ad vector. Hepatic LPLAT10 mRNA and protein expression in Ad-LPLAT10-treated mice was much higher than that in mice treated with control Ad vector. Induction of glucose-stimulated insulin secretion (GSIS) suppressed postprandial hyperglycemia in Ad-LPLAT10-treated mice compared with that in control Ad-vector-treated mice. Hepatic and serum levels of phosphatidylcholine, containing polyunsaturated fatty acid, were elevated in Ad-LPLAT10-treated mice. Elevated phosphatidylcholine levels increased GSIS in mouse insulinoma cells. Our study suggests that LPLAT10 is a promising new therapeutic target for T2DM.