Brace, from Pontarddulais, first played for Gorseinon Youth before entering a senior playing career which included games for Aberavon, Newport and Llanelli, Crawshays and the Barbarians..
He also played for Cardiff before going on to Oxford where he won his Blue and in 1953 played against the All Blacks for his club team, Newport.
Brace won his caps in his favoured position of scrum half but was also renowned as a capable outside half at senior level.
After his rugby career he began work as a broadcaster and succeeded former Wales and British and Irish Lions captain Cliff Morgan as Head of Sport at BBC Wales.
It was Cliff Morgan who partnered Brace at half back for Wales when he made his international debut.
The Group Chief Executive of the WRU, Roger Lewis, said:"All of us involved in Welsh rugby would like to send our condolences to the family and friends of Onllwyn Brace at this sad time.
"Onllwyn was not only a courteous gentleman but a superb rugby player who epitomised the value of bringing exceptional skill and flair to the field of play.
"He had all the attacking skills and was a great contributor both on and off the field to the strength of Welsh rugby.
"Onllwyn was always very supportive and I have fond memories of meeting him at the Llantwit Major RFC supper club.
"In his broadcast career he brought his love of rugby to the fore and made a great contribution to the coverage of the game in Wales."
Brian Sparks, who played seven times for Wales from 1954 to 1957, has passed away aged 82.
Following his return to Wales after playing Rugby League for Halifax and Salford, Brian played a huge part in promoting basketball in schools and elsewhere in south Wales, as a result of this Brian was awarded the MBE in 2012.
His funeral will take place at Coychurch Crematorium on Monday, 8th. July at 1.15 pm.