Reports indicate that he collapsed and died at his house on Tuesday night.
He played for Kenya Simbas from April 2012 for six years before moving to Impala, Strathmore, Homeboyz and most recently KCB.
Tony Onyango was part of the squad that reached the 2012/13 Kenya Cup Final.
The Maseno School alumnus also played for Kenya Sevens during the 2014/15 season under head coach Paul Treu.
Kenyans took to Twitter to express their grief describing him as ‘lionhearted’.
It’s a sad morning waking up to news of the sudden demise of @kcbrugby and @KenyaSimbas player Tony Onyango.
Our sincere condolences to his family, friends and the entire KCB rugby fraternity.
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Fierce in the field of rugby, Kenya's wing Tony Onyango was
a great player with a dedication. So sad you left us
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Fare thee well Tony Onyango, Heaven RFC have received a proper fullback... Keep playing the beautiful game man......
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Till we all cross that white line. RIP Tony Onyangotwitter.com/EricNjiiru/sta…
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Rest in Peace Tony Onyango. Untimely to say the least. May the good Lord provide comfort to Tony's Family , close friends and to the larger Rugby fraternity .
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Thank you for everything Tony Onyango. You gave your all for this country, for the rugby game and everything life shared with you. Rest easy
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RIP to Kenya Simbas, Kenya 7s and KCB Rugby star Tony Onyango who died on March 3, 2020.
Tony and I were friends since the days he played for @HomeboyzRugby and worked at @homeboyzkenya
My thoughts and prayers are with the family of Tony Onyango Opondo (Captain Maseno School Rugby 2009) now KCB. This happened at his home in Ngong last night
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