Thomas was best known for his role as match-day announcer at the Scarlets.
A statement from the Scarlets read: “We are devastated to hear the voice of Parc y Scarlets, Andrew ‘Tommo’ Thomas, has passed away suddenly.
“Tommo was a hugely popular figure as the Parc y Scarlets match-day announcer, a passionate Scarlets fan who brought his character and energy to every match.”
Scarlets chaplain Reverend Eldon Phillips added: “We are devastated to hear this tragic news. Tommo loved the Scarlets and put his heart and soul into his role as our match-day announcer.
“A huge character, he was much loved by supporters, players and staff.
“Our thoughts and prayers are with his wife Donna and son Cian at this sad time.”
A number of Scarlets players and coaches both past and present added their tributes.
Scarlets head coach Glenn Delaney said: “This is desperately sad news. Tommo will be greatly missed by us all. I’ll miss his smile, energy and passion.
“Gone too soon, much love to his family at this terrible time. #RIPTommo.”
Former second row and now Munster lock Tadhg Beirne said: “Very sad news to hear of the passing of Tommo. An absolute gentleman, a passionate Welshman, and a true Scarlet.
“My thoughts and condolences to his family and all at @scarlets_rugby. #RIPTommo.”
Former Wales and Scarlets back Morgan Stoddart said: “Hearing of the passing of @TOMMORADIO, dreadful news. What a great man. He brought laughter to any room he entered.
“Will be remembered and missed. #TrueScarlet.”
Scarlets back-row Uzair Cassiem said: “Devastated by the news of your passing! Always got the biggest smile, big handshake before and after games! To the family and friends of Andrew ‘Tommo’ Thomas, condolences from my family and myself.”
Scarlets and Wales prop Rob Evans said: “Really sad to hear the news about Tommo. Thoughts are with his family, a great man full of laughs.”
Former Wales and Scarlets hooker and captain Matthew Rees added: “Can’t believe the news coming from west tonight. Tommo you were a true gent. PYS will never be the same!!
Top Welsh referee Nigel Owens, who hails from west Wales, said: “Well I am devastated. A great man and a true friend. I can’t believe it. Always had a smile on his face.
Rupert Moon added: “Lost a great friend @TOMMORADIO my brother by another mother. Thoughts with his family and all his many friends. Sleep well buddy.”
The Scarlets’ fellow Welsh regions also added their support.
Cardiff Blues tweeted: “Thinking of everyone at Scarlets and Tommo’s friends and family. A larger than life character who will be missed by all of us.”
Dragons tweeted: “Desperately sad news from our friends @scarlets_rugby – the voice of Parc y Scarlets who was always a friendly and familiar face on our trips west.
“The thoughts of everyone @dragonsrugby go out to Tommo’s friends and family #RIPTommo.”
Ospreys tweeted: “We are deeply saddened to hear about the sudden loss of the voice of Parc Y Scarlets, Tommo. The thoughts of everyone at the Ospreys are with his family and friends and @scarlets_rugby at this sad time.”