Born in Edinburgh and educated at Cheltenham College and Oxford University where he studied Philosophy and Theology, he played in two victorious 'Blues' matches
From Oxford he signed a full-time contract with Bath and within two years had made his full International debut for Scotland against Italy in 2003, ahead of the start of the Rugby World Cup.
The strong-running back has gone on to be capped 32 times by his country, playing in two World Cups and scoring eight tries.
Commenting on his decision to retire, Danielli said: "Having been advised that I am no longer able to achieve the level of fitness required to play professional rugby, it is with great sadness that I announce my retirement from the game.
"I feel privileged to have been playing for over a decade and have thoroughly enjoyed my time as a professional rugby player, particularly my last five years here at Ulster.
"I would like to thank everyone who has helped me throughout my time here, to all the players, coaches, other members of staff and not least the fantastic supporters at Ulster that rival anywhere else in Europe, creating an atmosphere that has given me many special lifelong memories."
The 32-year-old added: "I wish the boys the very best of luck for the biggest of games next week and long into the future, the province is well on the path to becoming a leading force in European rugby and I will be in the stands cheering them towards this for years to come."