The present invention provides a one-part dental adhesive that exhibits excellent adhesive properties to both enamel and dentin and that has high storage stability and ambient-light stability. The present invention is a one-part dental adhesive including 1 to 30 weight% of a phosphoric acid group-containing monofunctional (meth)acrylate compound (a), 10 to 50 weight% of a water-soluble polymerizable monomer (b), 5 to 50 weight% of a hydrophobic crosslinkable (meth)acrylate compound (c), water (d), and a polymerization initiator (e). The water-soluble polymerizable monomer (b) includes a combination of a monofunctional (meth)acrylamide compound (b-1) having a particular structure and a water-soluble crosslinkable (meth)acrylic monomer (b-2). The weight ratio between the monofunctional (meth)acrylamide compound (b-1) and the water-soluble crosslinkable (meth)acrylic monomer (b-2) is 10 : 1 to 1 : 5.