Lǚ Yánjì 呂延濟 (fl. 718) was a Tang scholar who, while serving as xiànwèi 縣尉 (county sub-prefect) of Chángshān 常山 district in Qúzhōu 衢州, was recruited by Lǚ Yánzuò 呂延祚 (Vice-Minister of Works) to co-author what became known as the Wǔchén jízhù Wén xuǎn 五臣集註文選, the Five Officials’ interpretive commentary on Xiāo Tǒng’s anthology. The work was presented to Tang Xuánzōng on the tenth day of the ninth month of Kāiyuán 6 (718). Lǚ Yánjì’s commentary appears in KR4h0003. He is otherwise unattested in the standard histories; CBDB has no entry. Nothing of his biography survives beyond the Kāiyuán memorial.