Sealed web retractors and associated systems and methods for retracting a web, such as seat belt web, are disclosed herein. In one embodiment, a web retractor includes a frame having a sidewall with a first opening, a locking assembly attached to the frame and having a housing with a second opening adjacent to the first opening, and a shaft coupler rotatably and sealably carried by the sidewall. The shaft coupler operably couples a spool shaft to the locking assembly through the first and second openings. At least one seal is operably positioned in the first opening between the shaft coupler and the sidewall.