Abstract: Shock absorbing seat belt height adjusters for use with vehicle occupant restraint systems, and associated systems and methods. In one embodiment, a shock absorbing height adjuster can be attached to a vehicle frame between an upper anchor point and a lower anchor point adjacent to an occupant's shoulder. The height adjuster can include a web clamp that locates a D-ring for positioning a shoulder web portion of the restraint web at a desired height that is comfortable for the occupant. Additionally, the height adjuster can include an anti-cinch feature that can elastically extend in response to tension loads in the shoulder web portion, thereby reducing shock loads from being transmitted to the seat occupant from the shoulder web portion.