Robert Cosby Jr., Son of 'RHOSLC' Star Mary Cosby, Dies at 23

Cosby's ex-wife Alexiana Arian Smokoff is 'shaken up' after his unexpected passing.

Published on Feb. 26, 2026

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Robert Cosby Jr., the 23-year-old son of Real Housewives of Salt Lake City star Mary Cosby, has died. His ex-wife Alexiana Arian Smokoff is mourning his loss, with a source saying she is 'pretty shaken up' and 'everyone is upset' over his passing. An official cause of death has not yet been revealed.

Why it matters

Robert Cosby Jr.'s death is a tragic loss for his family, especially his mother Mary Cosby, who has been open about his struggles with substance abuse on the reality TV show. His tumultuous relationship and divorce from Alexiana Arian Smokoff also added complexity to his personal life in the final years.

The details

Robert Cosby Jr. and Alexiana Arian Smokoff had filed for divorce in November 2025, weeks after he was arrested for violating a protective order against her. Prior to their split, both had struggled with substance abuse issues. Alexiana had gone through rehab and was working to get her life back on track, while Robert continued to have legal troubles related to his ex-wife. He was released from police custody just two weeks before his death following a potential overdose.

  • Robert Cosby Jr. died on February 25, 2026.
  • Alexiana Arian Smokoff and Robert Cosby Jr. filed for divorce in November 2025.
  • Robert Cosby Jr. was arrested for violating a protective order against Alexiana in late 2025.

The players

Robert Cosby Jr.

The 23-year-old son of Real Housewives of Salt Lake City star Mary Cosby, who passed away unexpectedly.

Alexiana Arian Smokoff

Robert Cosby Jr.'s ex-wife, who is 'shaken up' after his death.

Mary Cosby

The Real Housewives of Salt Lake City star and mother of Robert Cosby Jr.

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What they’re saying

“Alexiana knows he passed away. She is pretty shaken up.”

— Source, Insider (Us Weekly)

“Everyone is upset. Everyone loved Robert.”

— Source, Insider (Us Weekly)

“Our beloved son Robert Jr. has been called home to the Lord. Though our hearts ache, we take comfort in God's promise and in knowing he is finally at peace. We are grateful for your prayers and trust in the Lord to carry us through this time of sorrow.”

— Mary Cosby (Statement)

The takeaway

This tragic loss highlights the ongoing challenges that reality TV stars and their families can face, including substance abuse issues and tumultuous personal relationships. It serves as a somber reminder of the importance of mental health support and resources for young people struggling with addiction.