The Japan Railway Construction, Transport and Technology Agency (鉄道建設・運輸施設整備支援機構, Tetsudō Kensetsu Un'yu Shisetsu Seibi Shien Kikō), or JRTT, is an Independent Administrative Institution (独立行政法人, Dokuritsu gyōsei hōjin) created by an Act of the National Diet, effective 1 October 2003.

As its name implies, JRTT is involved in construction and technical support for railway and other transportation projects throughout Japan.

In addition to its railway construction projects, JRTT has also sponsored maritime research, including the latest ship used as the JR Miyajima Ferry.

JRTT also performs administrative functions related to the liquidation of the Japanese National Railways, such as management of JNR employee pensions.

JRTT is currently the parent entity of the following JR Group companies: In 2011, the National Diet passed legislation requiring JRTT to use its retained earnings from other businesses for the purpose of Shinkansen construction and capital expenditures at its subsidiary railway companies.