Sydney Thelwall (born 18 December 1834 — 28 August 1922) was an English clergyman and Christian scholar.
He was admitted as a pensioner to Christ's College, Cambridge under Messrs Gell, Hays and Gunson on 9 October 1858.
Though he kept some terms after his first admission, he needed to be readmitted 30 September 1863, and was also admitted as a scholar of the college (under the tutorial care of Rysley) on 28 October 1863.
Ordained deacon at Exeter in 1865, and priest in 1866, he was curate of St Paul, Devonport from 1865 to 1867, and assistant-master at Plymouth Grammar School.
Telwall translated Tertullian in Clark's Ante-Nicene Fathers (Vols.