A glass core, a multilayer circuit board, and a method of manufacturing a glass core that appropriately form copper wiring, and suppresses crack and the like, a glass core includes: a glass plate; a first metal layer provided on the glass plate; a first electrolytic copper plating layer provided on the first metal layer; a dielectric layer provided above the first electrolytic copper plating layer; a second metal layer provided on the dielectric layer; an electroless nickel plating layer provided on the second metal layer and having a phosphorus content of less than 5 mass %; and a second electrolytic copper plating layer provided on the electroless nickel plating layer.