|Player||Country||Born||Match||Ground||Age at Match Start||Score|
|1||Sobers, G S A||West Indies||28/07/1936||26/02/1958 v. Pakistan||Sabina Park||21 years 213 days||365*|
|2||Bradman, D G||Australia||27/08/1908||11/07/1930 v. England||Headingley||21 years 318 days||334|
|3||Hutton, L||England||23/06/1916||20/08/1938 v. Australia||Kennington Oval||22 years 58 days||364|
|4||Hanif Mohammad||Pakistan||21/12/1934||17/01/1958 v. West Indies||Kensington Oval||23 years 27 days||337|
|5||Lara, B C||West Indies||02/05/1969||16/04/1994 v. England||Antigua Recreation Ground||24 years 349 days||375|
|6||Rowe, L G||West Indies||08/01/1949||06/03/1974 v. England||Kensington Oval||25 years 57 days||302|
|7||Cowper, R M||Australia||05/10/1940||11/02/1966 v. England||Melbourne Cricket Ground||25 years 129 days||307|
|8||Sehwag, V*||India||20/10/1978||28/03/2004 v. Pakistan||Multan Cricket Stadium||25 years 160 days||309|
|9||Gayle, C H*||West Indies||21/09/1979||29/04/2005 v. South Africa||Antigua Recreation Ground||25 years 220 days||317|
|10||Edrich, J H||England||21/06/1937||08/07/1965 v. New Zealand||Headingley||28 years 17 days||310*|
|11||Jayasuriya, S T||Sri Lanka||30/06/1969||02/08/1997 v. India||R. Premadasa Stadium||28 years 33 days||340|
|12||Simpson, R B||Australia||03/02/1936||23/07/1964 v. England||Old Trafford||28 years 171 days||311|
|13||Jayawardene, D P M*||Sri Lanka||27/05/1977||27/07/2006 v. South Africa||Sinhalese Sports Club Ground||29 years 61 days||374|
|14||Amla, H M*||South Africa||31/03/1983||19/07/2012 v. England||Kennington Oval||29 years 110 days||311*|
|15||Hammond, W R||England||19/06/1903||31/03/1933 v. New Zealand||Eden Park||29 years 285 days||336*|
Virender Sehwag is the only to score a triple century in Test cricket. Sehwag is No. 8 in this list. He was 25 years and 160 days old when he smashed his first triple century in Test cricket against Pakistan in Multan.
West Indies’ legend Gary Sobers is the youngest batsman to score a triple century in Test cricket. Sobers was 21 years and 213 days old when he scored his first triple century, way back in 1958 vs Pakistan at Sabina Park.
Another West Indian, and one of the greatest batsmen to have ever played the game, Brian Lara, is also in the list. Lara was 24 years and 349 days old when he scored his first triple century in Test cricket. Lara is also the only batsman to score 400 runs in a single innings of a Test match.
Stats via HowStat.com