魏定国在《水浒新传》等文学作品中有他的形象，亦出现于评书和影视剧中

《水浒传》衍生小说中魏定国的人物结局介绍
俞万春的《荡寇志》中，魏定国随呼延灼守嘉祥，驻军南旺营。后在嘉祥城下与闻达交战，被闻达用拖刀计擒获，监禁于兖州府。最终被押赴京城，凌迟处死。                                                                                                                                                                                                                     程善之的《残水浒》中，魏定国是梁山军官团成员，随卢俊义投降朝廷，按原官品开复。                                                                                                                                                                                                                                                                                                                                     巴孤的《贼三国》中，魏定国是宋国安北将军。后随吴用迎战司马懿，围攻翟阳时遇到西凉援军，被刘封刺死。他有自制的药膏，涂在身上能避烟火灼烧。                                                                                                                                                                                                                            姜鸿飞的《水浒中传》中，魏定国随征辽国，在青石谷夜战中阵亡。                                                                                                                                                                                                                                                                                                                                                                     张恨水的《水浒新传》中，魏定国参与抗金，北宋灭亡后被汉奸范琼用毒酒毒死在白莲寺。褚同庆的《水浒新传》中，魏定国原是隰州城防提辖，随关胜抗辽有功，升任本州都监。后随关胜征讨梁山，被擒投降。他在梁山排第五十三位，星号地火星，担任马军副骠骑将，镇守宛子城前军大寨。最终随宋江受招安。
 

魏定国的相关评书及影视形象介绍
扬州评话王派水浒中，魏定国是关胜的结拜兄弟，随其镇守山海关，并在关胜征山时负责留守。后也率军征剿梁山，未与关胜交战便被劝降。他将一种药草烧出来的烟装在葫芦里，作战时放烟熏人，能熏得人睁不开眼，而且奇痒无比。                                                                                           2011年《新水浒传》，姜孝萌饰演魏定国。