Apart from having scored more than 3000 runs in international cricket, O'Brien has played 176 first-class matches for 9057 runs representing Kent, Northamptonshire and Leicestershire in the English county circuit. His domestic career also saw him play 238 List A matches and 147 T20s.
"It is with a heavy heart that I am announcing my retirement from international and professional cricket," he said. "I have been blessed to have been lucky enough to have represented my country for 16 years with plenty more ups than downs and for this I look back with nothing but smiles and laughter.
"I would like to thank all my coaches and team-mates who along the way have helped me become the player I was. I have had too many coaches to mention them all but a special thanks must go to Adrian 'Adi' Birrell who took a chance on me in 2002 and who arranged a trial at Kent from where I started my 14-year county career, which was an absolute privilege and an honour.
"I always tried to play with a smile on my face and with an enjoyment that I think all people could see whether watching from the stands, standing with me in the field or coming up against me for the opposition. Hard work was always behind my performance and I will take this same ethos into the next phase of my career where I have been working in the sports agency business for the last 2 years alongside my playing commitments and will continue to pursue this avenue."
O'Brien is the second high-profile cricketer after Ed Joyce to end career after the historic Test against Pakistan. He played his last match for Ireland against Afghanistan in August.
The left-handed batsman has been a part of Ireland's rise through the years, and was their hero in the famous win over Pakistan in the World Cup 2007. Chasing 128, he made 72 in a three-wicket win to seal the game and also won the Man of the Match award. He was also a part of the sides that defeated England in the World Cup 2011 and West Indies in the World Cup 2015. He is one of only four Ireland players to have played more than 100 ODIs and has also featured in four World T20s.
"To all at Cricket Ireland a sincere thank you for allowing me to wear the shamrock for 16 years," he said. "There are too many fond memories to mention so I just wish the team and the organisation all the very best for the future and I will be watching keenly from afar. From playing relatively small fixtures at the start of my career to competing and winning World Cup matches to being there to play in our first Test match meant I have achieved more than I could have ever dreamt and for this I look back with nothing but fondness.
"Finally, and most importantly, thank you to my family for all the guidance and support down the years whether it was driving me to matches, throwing balls to me in the garden or travelling to the Caribbean to watch me play. Without you I would not have amounted to anything on the field so a huge thank you to all the O'Briens. Now is a time for myself and my wonderful wife Bex to welcome our new addition into the world and enjoy some family time together."
William Porterfield, Ireland's Test and ODI captain, paid tribute to O'Brien saying he can be proud of his achievements for the country.
"It's always a sad time when someone who has had a great career and played such a big part in the evolution of Irish cricket goes," he said. "Niall, along with the likes of Ed Joyce, showed what was possible at the time for young Irish cricketers, in forging a great career in the county game. Alongside that he had a great international career. Niall would have been involved when we only had a couple of games a year, and I'm sure he will sit back and reflect with great pride when he sees where he has helped get Ireland to. From his Man-of-the-Match innings in the 2007 World Cup that helped put Ireland on the global map, to walking out in Ireland's inaugural Test match.
"He can be immensely proud of that and everything else he achieved in his career and fully deserves all the plaudits I'm sure he will get. I would personally like to wish him all the very best for a successful future."
First Published: October 12, 2018, 6:49 PM IST