| RTPI | RÁdio Televisão Portuguesa Internacional (Portuguese TV Channel) | RÁdio Televisão Portuguesa Internacional (Portuguese TV Channel) |
| RTPI | Real Time Passenger Information | 实时乘客信息 |
| RTPI | Randy Torgerson, Private Investigator | Randy Torgerson，私人调查员 |
| RTPI | Roger Tory Peterson Institute | 罗杰·托利·彼得森研究所 |
| RTPI | Radio Tele Providence Internationale | 国际广播电台 |
| RTPI | Royal Town Planning Institute | 皇家城市规划研究所 |
| RTPI | Royal Town Planning Institute (Scotland) | 皇家城市规划研究所（苏格兰） |