Invite friends and family to read the obituary and add memories.
We'll notify you when service details or new memories are added.
You're now following this obituary
We'll email you when there are updates.
Select your format and elements to print
Thomas F. O'Brien, 74, of Casper, Wyoming passed away Saturday, September 5, 2026. Tom was born in Casper on February 20, 1952 the fourth of five sons to Con and Mary O'Brien. Tom graduated from Natrona County High School and received his Bachelor's degree from Casper College/University of Wyoming.
As a young man, Tom worked on his parents ranch north of Casper during the summers. He worked at Casper College as a custodian in the late 1970s. In the 1980s Tom worked for the U.S. Bureau of Census and as a tax preparer. In 2000 Tom landed a job as a substitute teacher for the Natrona County School District.
Tom loved leather crafting and had an insatiable appetite for reading, particularly news magazines and newspapers. He had a heart for volunteering with the Holy Cross Brothers with cleaning, bake sales, and catering. Tom became involved and served on the board as a representative with NAMI (National Alliance for Mental Illness) - Casper. He was a lifelong member of St. Anthony's Catholic Church and its ministries. The number of cinnamon rolls, cookies, and quiches Tom helped Brother Raymond bake is in the thousands. His heart of service extended to caring for his parents and many other friends in their declining years.
He was preceded in death by his parents; brother, Con, Jr.; and Godmother, Polly Marinich.
He is survived by brothers, John (Lynda) O'Brien; Michael (Sharon) O'Brien; and Daniel O'Brien; nieces, Laura O'Brien; Kelli Weisgerber; Darcy (Dan) Genrich; Keegan O'Brien; and Connie (Dan) Stansbury; nephews, Michael O'Brien, Jr.; Frank O'Brien; and Robert O'Brien; grand niece, Sophia Louis and An Nguyen; and grand nephew, Caden Louis.
In lieu of flowers please consider donating to causes that Thomas felt passionately about: Holy Cross Center, 1030 N Lincoln St, Casper, WY 82601, Casper College Alumni Association, 125 College Dr., Walter H. Nolte Gateway Center, #306, Casper, WY 82601, or National Alliance for Mental Illness, PO Box 1883, Casper, WY 82602.
Vigil is at 5 pm on Thursday, September 17, 2026 followed by the Rosary at 6 pm at Newcomer Funeral Home, 710 E 2nd St, Casper WY 82601. The funeral is at 10 am on Friday, September 18, 2026 at St. Anthony's Catholic Church, 604 S Center St, Casper, WY 82601 with burial immediately following at Highland Cemetery.
To share a memory of Tom or leave a special message for the family, please visit the guestbook below.
Thursday, September 17, 2026
5:00 - 6:00 pm (Mountain time)
Newcomer Funeral Home
Thursday, September 17, 2026
6:00 - 6:30 pm (Mountain time)
Newcomer Funeral Home
Friday, September 18, 2026
Starts at 10:00 am (Mountain time)
St. Anthony's Catholic Church
Friday, September 18, 2026
Starts at 11:00 am (Mountain time)
Highland Cemetery
Visits: 864
This site is protected by reCAPTCHA and the
Google Privacy Policy and Terms of Service apply.
Service map data © OpenStreetMap contributors