格雷厄姆·约翰·约斯特（Graham John Yost，1959年9月5日-），加拿大影视编剧。他最著名的作品是电影《速度》、《断箭》和《大雨》以及电视剧《正义》。2002年，他创作了广受好评但短命的电视剧《Boomtown》。

他还为电视连续剧《赫尔曼的头和兄弟连》撰稿。他还创作了短命的 NBC 电视剧《雷恩斯》。约斯特与汤姆·汉克斯和史蒂文·斯皮尔伯格以及他的两位 Boomtown 编剧米歇尔·阿什福德和拉里·安德里斯合作，编写并执导了 HBO 迷你剧《太平洋》的剧集。截至 2010 年，Yost 是 Justified 系列的创作者和执行制片人，该系列于 2010 年 3 月在 FX 上首播。

他出生于怡陶碧谷，是加拿大电视名人埃尔维·约斯特（Elwy Yost）的儿子，埃尔维·约斯特（Elwy Yost）是公共广播公司TVOntario的《周六电影之夜》的长期主持人。他和家人住在加利福尼亚。

Graham John Yost (born September 5, 1959) is a Canadian film and television screenwriter. His best-known works are the films Speed, Broken Arrow, and Hard Rain and the TV series Justified. In 2002, he created the widely acclaimed, yet short-lived drama series Boomtown.

He has also written for the television series Herman's Head and Band of Brothers. He also created the short-lived NBC drama Raines. Yost teamed up with Tom Hanks and Steven Spielberg, along with two of his fellow Boomtown writers Michelle Ashford and Larry Andries, to write and direct episodes of the HBO miniseries The Pacific. As of 2010, Yost is the creator and executive producer of the series Justified, which premiered on FX in March 2010.

Born in Etobicoke, he is the son of Canadian television personality Elwy Yost, the longtime host of the public broadcaster TVOntario's Saturday Night at the Movies. He lives in California with his family.