イスタンブールのガラタ地区（現在のカラキョイ）に外交官の三男として生まれる。父親ルイ・シェニエはフランスのラングドック出身で、レバント方面で20年にわたって織物商人として働いた後、イスタンブールでフランス大使相当の地位に任ぜられていた。ギリシャ系の母エリザベト・サンティ＝ロマカは、19世紀の歴史家・政治家のアドルフ・ティエールの祖母と姉妹であった。アンドレが3歳のとき、一家はフランス王国に戻り、父親が1768年から1775年までモロッコでフランス領事を務めるものの、家族はその間フランスに留まった。数年間カルカッソンヌのおばのもとで自由奔放に育った後、パリのコレージュ・ド・ナヴァールにおいて、古典文学の詩の翻訳家として名を揚げた。1783年にストラスブールのフランス連隊に士官候補生名簿に登載されるが、新たな経験は間もなく潰えてしまう。年末までにパリに戻り、家族の歓待を受けるとともに、母親のサロンに足繁く通った洗練された社交界の常連、とりわけルブラン・＝パンダール、ラヴォワジエ、ルジュール、ドラや、少し後にはダヴィッドらと交際する。この頃にはすでに詩人になろうと決めており、当時の新古典主義に参加しようと決心していた。特に、1784年にローマやナポリ、ポンペイを訪れたことから、強く刺激された。ほぼ3年の間シェニエは、家族からプレッシャーや干渉を受けることなく、詩作を研究し試作に向けた。この時期、テオクリトスやビオーン、古代ギリシャの詞花集を大幅に模倣し、主に田園詩や牧歌を書いた。この頃に書かれたか、少なくともスケッチされた詩に、「 L'Oaristys 」「 L'Aveugle 」「 La Jeune Malode 」「 Bacchus 」「Euphrosine 」「 La Jeune Tarentine 」があり、古代神話と、個人の感情や精神という感覚を融合させた。田園詩やエレジー以外にも、教訓詩や哲学詩の詩作にも挑戦し,1783年にHermesの述作を始めた時には、いくらかルクレティウス流に、ドゥニ・ディドロの百科全書を凝縮して長編詩にすることを目指していた。現存しているのは断片のみであるが、この詩は、宇宙における人間の立場について触れているもので、始めは孤立した状態として、そして次に社会的な状態として扱っている。また別の断片である"L'Invention"には、シェニエの詩歌に対する考え方が述べられている。1787年に一家の友人であったアンヌ＝セザール・ド・ラ・リュゼルヌが駐英フランス大使に任ぜられた際、シェニエはその秘書に指名され、3年間ロンドンに滞在することになる。だがその生活は必ずしも幸福ではなかった。イギリスではミルトンとジェームズ・トムソンに興味を示し、いくつかの自作の詩にはシェイクスピアやトマス・グレイの影響が見られるとはいえ、英文学を学んだというには程遠かった。The events of 1789 and the startling success of his younger brother, Marie-Joseph, as political playwright and pamphleteer, concentrated all his thoughts upon France. In April 1790 he could stand London no longer, and once more joined his parents at Paris in the rue de Cléry. France was on the verge of anarchy. A strong believer in constitutional monarchism, Chénier believed that the French Revolution was already complete and that all that remained to be done was the inauguration of the reign of law. Though his political viewpoint was moderate, his tactics were dangerously aggressive: he abandoned his gentle idyls to write poetical satires.  His prose "Avis au peuple Français" (24 August 1790) was followed by the rhetorical "Jeu de paume", a somewhat declamatory moral ode addressed to the painter Jacques-Louis David.In the meantime he orated at the Feuillants Club, and contributed frequently to the Journal de Paris from November 1791 to July 1792, when he wrote his scorching iambs to Jean Marie Collot d'Herbois, Sur les Suisses révoltés du regiment de Châteauvieux. The insurrection of 10 August 1792 uprooted his party, his paper and his friends, and he only escaped the September Massacres by staying with relatives in Normandy.  In the month following these events his brother, Marie-Joseph, had entered the anti-monarchical National Convention. André raged against all these events, in such poems as Ode à Charlotte Corday congratulating France that "Un scélérat de moins rampe dans cette fange." At the request of Malesherbes, the defense counsel to King Louis XVI, Chénier provided some arguments to the king's defense.After the king's execution he sought a secluded retreat on the Plateau de Satory at Versailles and only went out after nightfall. There he wrote the poems inspired by Fanny (Mme Laurent Lecoulteux), including the exquisite "Ode à Versailles". His solitary life at Versailles lasted nearly a year. On 7 March 1794 he was arrested at the house of Mme Piscatory at Passy. Two obscure agents of the Committee of Public Safety (one of them named Nicolas Guénot) were in search of a marquise who had fled, but an unknown stranger was found in the house and arrested on suspicion of being the aristocrat they were searching for. This was Chénier, who had come on a visit of sympathy. He was taken to the Luxembourg Palace and afterwards to Saint-Lazare. During the 140 days of his imprisonment he wrote a series of iambs denouncing the Convention (in alternate lines of 12 and 8 syllables), which, in the words of the 1911 Encyclopædia Britannica, "hiss and stab like poisoned bullets", and which were smuggled to his family by a jailer.  In prison he also composed his most famous poem, "Jeune captive", a poem at once of enchantment and of despair.  Ten days before Chénier's death, the painter Joseph-Benoît Suvée completed the well-known portrait of him. Chénier might have been overlooked but for the well-meant, indignant officiousness of his father. Marie-Joseph did his best to prevent his brother's execution, but he could do nothing more.  Maximilien Robespierre, who was himself in dangerous straits, remembered Chénier as the author of the venomous verses in the Journal de Paris and sentenced him to death. Chénier was one of the last persons executed by Robespierre.  At sundown, Chénier was taken by cart to the guillotine at what is now the Place de la Nation.  He was executed along with a Princess of Monaco, on a bogus charge of conspiracy.  Three days later Robespierre was seized and executed without trial, ending the Terror.  Chénier, aged 31 at his execution, was interred in the Cimetière de Picpus.The record of Chénier's last moments by Henri de Latouche is rather melodramatic and is certainly not above suspicion.