Chén Shìyuán 陳士元 (b. 1516, d. unclear; conventionally placed late 16th century), zì Xīnshū 心叔, hào Huánzhōngzǐ 環中子, was a mid-to-late-Míng polymath from Yìngchéng 應城 (Déān 德安, modern Húběi 湖北). He passed the jìnshì examination in Jiājìng jiǎchén 嘉靖甲辰 = 1544 and held office as Prefect of Luánzhōu 灤州.
His scholarly output spans the Yìjīng, the Mèngzǐ, dream-divination, surname-studies, and miscellaneous philology. The works circulate as parts of his Guī yún biéjí 歸雲別集 — the title Guī yún (Returning Cloud) reflects his late-life retreat from office. His principal Yìjīng writing is the Yì xiàng gōu jiě 易象鈎解 (KR1a0099), composed circa 1544 and onward and incorporated into juàn 58–61 of the Guī yún biéjí; he also produced a shorter Yì xiàng huì jiě 易象彙解 in two juàn (now lost or unseen by the Sìkù editors). His Méngzǐ záji 孟子雜記 and Mèng lì xuán jié 夢林玄解 (a major dream-interpretation manual) are also widely circulated.
CBDB id 203527 has 1516 as birth year; death year is open. Standard Míng biographical sources do not give a confident death year.