張安世（？ - 前62年），字子孺，京兆杜陵人（今西安市東南），西漢漢武帝到漢宣帝時代的三朝重臣。

他是著名酷吏張湯之子，受父蔭在少年時代即做郎官，到尚書令手下做事。張湯被迫自殺後，漢武帝繼續重用張安世，任尚書令、升任光祿大夫，太子劉據案發後受兄長張賀牽連；漢昭帝時，霍光滅掉其他的託孤大臣上官桀、桑弘羊與鄂邑長公主、燕王劉旦之後，任命張安世為右將軍光祿勛，以輔佐有功，元鳳六年（公元前75年）封富平侯。張安世堅決反對兄長張賀把女兒嫁給前太子劉據的長孫劉病已。

昭帝暴亡後，霍光請求太后任命張安世為車騎將軍。張安世配合霍光立、廢昌邑王劉賀，改立劉病已為帝（漢宣帝）。宣帝為安撫張安世，把他的三個兒子千秋、延壽、彭祖入宮任職。霍光于地節二年（公元前68年）去世，張安世在御前力辭大將軍職銜，但仍被任命為大司馬車騎將軍，不久又改任大司馬衛將軍，領尚書事，集軍政大權於一身，以為官廉潔著稱。地節四年（前66年），宣帝族滅霍家，但赦免了嫁入霍家的張安世孫女張敬。張安世在宣帝一朝處事極為謹慎，最後平安告老。

其曾孫張臨，尚敬武公主，生子張放。

2007年，其墓地在西安南郊鳳棲原被發現，其墓葬級別非常高，與周圍張氏家族後代的墓地形成一個佔地廣大的家族墓地群。出土的「張」字銅印和「衛將長史」封泥，斷定大墓主人就是張安世。因為根據史書記載，西漢姓張的衛將軍唯有張安世一人。

顯示更多...: 世系圖   參考資料和注釋  

Zhang Anshi (張安世 Zhāng Ānshì; died 62 BCE), courtesy name Ziru (子孺), was a Chinese politician of the Han Dynasty. He was a son of Zhang Tang.

He was a precocious student who attracted attention in a famous incident. During an Imperial progress, to which he was attached in a subordinate capacity, three boxes of books were missing. However, he was able to repeat the contents of each so accurately that upon the recovery of the books, they were found to tally exactly with his description. Emperor Wu immediately appointed him to high office; Emperor Wu promoted him further after Zhang Tang's death.

He played a part in deposing Liu He as emperor, and subsequently rose under Emperor Xuan to be President of the Board of War, in succession to Huo Guang. After his death, his posthumous title was "Marquis Jing" (敬侯).

Zhang Anshi was well-known to be cautious in both his mannerisms and how he is perceived by others. As the President of the Board of War, he came to know that Emperor Xuan had promoted his son Yanshou. Anshi then attempted to resign his position, but was refused by Emperor Xuan. Later, he advised Yanshou to leave the capital and become an official elsewhere, as he worried that with both father and son in high positions within the capital, they would become targets.

Zhang Anshi's elder brother Zhang He was close to Emperor Wu's first crown prince Liu Ju. With Liu Ju's suicide after his failed rebellion, Zhang He was implicated and sentenced to death. Anshi pleaded for clemency; He's sentence was commuted to castration. Anshi's youngest son Pengzu was then given to He and regarded as He's heir.