A safety harness retaining device for a child seat has first and second parts. The first part has a body, a cover removably attached to the body to cover a first side of the body, a magnet enclosed by the cover and body, a pin attached to and extending from a second side of the body for piercing a covering of the child seat, and a clasp removably connectable to the pin for securing the first part to the covering. The second part has a strap configured to be wrapped around and secured to a safety harness belt of the child seat and has an encased ferrous material. And the first part and the second parts are removably connectable through a magnetic force between the magnet and the ferrous material.