Who makes kirkland signature moisturizing soap?

Kirkland Signature is Costco's own brand, so they don't disclose the specific manufacturer of their products, including the moisturizing soap.

However, it's likely that the Kirkland Signature moisturizing soap is manufactured by a third-party company that specializes in producing personal care items.

This is a common practice for large retailers like Costco, allowing them to focus on selling the products while outsourcing the manufacturing to experienced companies.