Robert Cosby Jr., the 23‑year‑old son of Real Housewives of Salt Lake City cast member Mary Cosby, has died following a reported medical emergency, TMZ first reported Wednesday. The cause of death has not yet been confirmed, but authorities responded to what was described as a possible overdose at an address in Salt Lake City, and the investigation remains active.
Salt Lake City police said officers were called Monday night for a “full arrest/medical emergency” involving a 23‑year‑old man. Fire crews and paramedics were also dispatched to the scene.
The tragic news comes months after his wife, Alexiana Smokoff, filed for divorce. Robert and Alexiana married in 2022 in a Utah courthouse — a union that later became a recurring storyline on RHOSLC.
Robert’s struggles with substance use and mental health were documented publicly both on and off the show. In RHOSLC Season 5, he spoke candidly with his mother about longstanding addiction issues, including dependence on prescription medications like Xanax and oxycodone, as well as other substances, which he said dated back to his teenage years.
In 2024, Robert entered rehab after testing positive for cocaine, fentanyl and marijuana, a move his mother said was a hopeful step in his sobriety journey; she shared that he completed a month‑long program and “came out a new person.”
Despite those efforts, he continued to face legal and personal challenges. Over the past few years, Robert had multiple run‑ins with the law, including a DUI arrest in 2022 — for which he pleaded guilty — and more recent arrests on charges including trespassing and assault in 2025.
Family and friends are now mourning the loss of a young life cut tragically short. Robert was only 23.
Note to readers: This is a developing story. Updates will be added as more information becomes available.