Twenty20 Batting and Fielding Against Each Opponent by Kevin O'Brien
| Opponent | Matches | Inns | Not Out | Runs | HS | Ave | 100 | 50 | Ct | St |
| Afghanistan | 18 | 18 | 0 | 271 | 74 | 15.05 | 0 | 1 | 5 | |
| Antigua Hawksbills | 3 | 3 | 1 | 99 | 90* | 49.50 | 0 | 1 | 3 | |
| Auckland | 2 | 2 | 0 | 75 | 52 | 37.50 | 0 | 1 | 1 | |
| Australia | 1 | 1 | 0 | 35 | 35 | 35.00 | 0 | 0 | 1 | |
| Balkh Legends | 1 | 1 | 0 | 1 | 1 | 1.00 | 0 | 0 | 0 | |
| Bangladesh | 5 | 4 | 1 | 44 | 39* | 14.66 | 0 | 0 | 1 | |
| Bangladesh A | 3 | 2 | 0 | 51 | 30 | 25.50 | 0 | 0 | 0 | |
| Barbados Tridents | 3 | 2 | 0 | 11 | 9 | 5.50 | 0 | 0 | 1 | |
| Barisal Burners | 2 | 2 | 1 | 35 | 29 | 35.00 | 0 | 0 | 1 | |
| Bermuda | 1 | 1 | 0 | 6 | 6 | 6.00 | 0 | 0 | 0 | |
| Canada | 4 | 3 | 0 | 40 | 31 | 13.33 | 0 | 0 | 2 | |
| Canterbury | 2 | 2 | 0 | 29 | 18 | 14.50 | 0 | 0 | 1 | |
| Central Districts | 2 | 2 | 0 | 17 | 12 | 8.50 | 0 | 0 | 0 | |
| Chittagong Kings | 2 | 2 | 1 | 19 | 13* | 19.00 | 0 | 0 | 0 | |
| Derbyshire | 4 | 2 | 0 | 40 | 31 | 20.00 | 0 | 0 | 0 | |
| Dhaka Gladiators | 2 | 2 | 0 | 20 | 20 | 10.00 | 0 | 0 | 0 | |
| Durham | 4 | 4 | 1 | 78 | 48* | 26.00 | 0 | 0 | 2 | |
| Duronto Rajshahi | 2 | 1 | 0 | 3 | 3 | 3.00 | 0 | 0 | 1 | |
| England | 1 | 0 | | | | | | | 0 | |
| Essex | 3 | 3 | 0 | 33 | 33 | 11.00 | 0 | 0 | 2 | |
| Glamorgan | 2 | 2 | 1 | 41 | 40* | 41.00 | 0 | 0 | 0 | |
| Gloucestershire | 1 | 1 | 0 | 8 | 8 | 8.00 | 0 | 0 | 0 | |
| Guyana Amazon Warriors | 5 | 5 | 0 | 109 | 70 | 21.80 | 0 | 1 | 2 | |
| Hampshire | 4 | 3 | 1 | 39 | 22 | 19.50 | 0 | 0 | 4 | |
| Hong Kong | 5 | 5 | 1 | 223 | 124 | 55.75 | 1 | 1 | 2 | |
| India | 3 | 3 | 0 | 12 | 10 | 4.00 | 0 | 0 | 2 | |
| Italy | 1 | 1 | 0 | 4 | 4 | 4.00 | 0 | 0 | 0 | |
| Jamaica Tallawahs | 4 | 4 | 0 | 56 | 32 | 14.00 | 0 | 0 | 1 | |
| Jersey | 2 | 2 | 0 | 19 | 11 | 9.50 | 0 | 0 | 3 | |
| Kent | 4 | 3 | 1 | 79 | 43* | 39.50 | 0 | 0 | 0 | |
| Kenya | 5 | 4 | 2 | 60 | 30* | 30.00 | 0 | 0 | 1 | |
| Khulna Royal Bengals | 1 | 1 | 1 | 24 | 24* | | 0 | 0 | 1 | |
| Lancashire | 3 | 3 | 0 | 85 | 47 | 28.33 | 0 | 0 | 0 | |
| Leicestershire | 1 | 0 | | | | | | | 0 | |
| Leinster Lightning | 3 | 3 | 1 | 83 | 64* | 41.50 | 0 | 1 | 0 | |
| Middlesex | 4 | 4 | 2 | 235 | 119 | 117.50 | 1 | 2 | 5 | |
| Munster Reds | 6 | 6 | 1 | 117 | 56 | 23.40 | 0 | 1 | 0 | |
| Namibia | 7 | 6 | 0 | 115 | 28 | 19.16 | 0 | 0 | 7 | |
| Nangarhar Leopards | 1 | 1 | 0 | 22 | 22 | 22.00 | 0 | 0 | 1 | |
| Nepal | 2 | 2 | 1 | 6 | 5 | 6.00 | 0 | 0 | 3 | |
| Netherlands | 13 | 12 | 2 | 254 | 46 | 25.40 | 0 | 0 | 5 | |
| New Zealand | 1 | 1 | 0 | 2 | 2 | 2.00 | 0 | 0 | 1 | |
| Nigeria | 1 | 1 | 0 | 32 | 32 | 32.00 | 0 | 0 | 0 | |
| North West Warriors | 9 | 9 | 1 | 183 | 82 | 22.87 | 0 | 1 | 2 | |
| Northamptonshire | 5 | 4 | 0 | 76 | 29 | 19.00 | 0 | 0 | 2 | |
| Northern Knights | 8 | 8 | 0 | 86 | 19 | 10.75 | 0 | 0 | 6 | |
| Nottinghamshire | 1 | 1 | 1 | 0 | 0* | | 0 | 0 | 0 | |
| Oman | 5 | 5 | 0 | 145 | 41 | 29.00 | 0 | 0 | 3 | |
| Otago | 2 | 2 | 0 | 5 | 5 | 2.50 | 0 | 0 | 0 | |
| Pakistan | 1 | 1 | 0 | 26 | 26 | 26.00 | 0 | 0 | 0 | |
| Papua New Guinea | 3 | 3 | 1 | 23 | 19* | 11.50 | 0 | 0 | 0 | |
| Scotland | 13 | 11 | 2 | 305 | 65 | 33.88 | 0 | 2 | 3 | |
| Somerset | 3 | 3 | 0 | 41 | 34 | 13.66 | 0 | 0 | 1 | |
| South Africa | 3 | 3 | 0 | 2 | 2 | 0.66 | 0 | 0 | 0 | |
| Sri Lanka | 2 | 2 | 0 | 5 | 5 | 2.50 | 0 | 0 | 0 | |
| Sri Lanka A | 1 | 1 | 0 | 11 | 11 | 11.00 | 0 | 0 | 0 | |
| St Lucia Zouks | 3 | 3 | 1 | 101 | 55* | 50.50 | 0 | 1 | 1 | |
| Surrey | 2 | 2 | 0 | 31 | 24 | 15.50 | 0 | 0 | 0 | |
| Sussex | 4 | 3 | 0 | 18 | 14 | 6.00 | 0 | 0 | 2 | |
| Sylhet Royals | 2 | 2 | 0 | 30 | 30 | 15.00 | 0 | 0 | 0 | |
| Uganda | 2 | 2 | 1 | 53 | 39* | 53.00 | 0 | 0 | 0 | |
| United Arab Emirates | 11 | 11 | 1 | 281 | 54 | 28.10 | 0 | 1 | 4 | |
| United States of America | 4 | 4 | 0 | 91 | 47 | 22.75 | 0 | 0 | 0 | |
| Warwickshire | 3 | 3 | 1 | 14 | 11 | 7.00 | 0 | 0 | 1 | |
| Wellington | 3 | 3 | 1 | 92 | 42 | 46.00 | 0 | 0 | 1 | |
| West Indies | 7 | 7 | 1 | 128 | 48 | 21.33 | 0 | 0 | 2 | |
| West Indies XI | 3 | 3 | 1 | 24 | 13 | 12.00 | 0 | 0 | 1 | |
| Worcestershire | 3 | 2 | 0 | 34 | 22 | 17.00 | 0 | 0 | 3 | |
| Yorkshire | 3 | 3 | 1 | 34 | 21 | 17.00 | 0 | 0 | 1 | |
| Zimbabwe | 8 | 8 | 0 | 206 | 60 | 25.75 | 0 | 1 | 2 | |