Sachin Tendulkar is the first and till now the only player to score a double century in ODI Cricket.
Sourav Ganguly Double Centuries in Test Cricket: One
Polly Umrigar was the first Indian to score double century in test cricket.
Brendon Kuruppu of Sri Lanka scored the slowest double century of Test Cricket in 2009 against New Zealand on 548 balls in 777 minutes.
Most double century record in Test Cricket is still in the name of Donald Bradman who scored 12 double centuries.
Sachin Tendulkar is the only player to score double century in one day international.