Cheng Kai-wen (Chinese: 鄭凱文; using "Cheng (ジェン)" as his registration until 2010, born July 26, 1988) is a Taiwanese professional baseball pitcher for the CTBC Brothers of the Chinese Professional Baseball League (CPBL).

He has previously played in Nippon Professional Baseball (NPB) for the Hanshin Tigers and Yokohama DeNA BayStars.

Cheng signed with the Yokohama DeNA BayStars of Nippon Professional Baseball for the 2013 season.

In parts of 10 seasons in the CPBL, Cheng accumulated a 76–51 record and 3.69 ERA with 718 strikeouts across 1,044+2⁄3 innings pitched.

He was selected Chinese Taipei national baseball team at the 2008 Summer Olympics, 2009 World Baseball Classic and 2018 MLB Japan All-Star Series exhibition game against Japan[2] This biographical article relating to a Taiwanese baseball figure is a stub.