Early life thumbnail|left|Sassoon (front) with his brother Hamo and other students on the morning after a college May Ball at Cambridge University in 1906 Siegfried Sassoon was born to a Jewish father and an Anglo-Catholic mother, and grew up in the neo-gothic mansion named Weirleigh (after its builder Harrison Weir) in Matfield, Kent. His father, Alfred Ezra Sassoon (1861–1895), son of Sassoon David Sassoon, was a member of the wealthy Baghdadi Jewish Sassoon merchant family. Siegfried's mother, Theresa, belonged to the Thornycroft family, sculptors responsible for many of the best-known statues in London; among them her brother, Sir Hamo Thornycroft.
eArly lIFe thumbnaIL|lefT|SASsoon (front) wiTH his brOtHer hamO AND oTheR STUDents on tHE morNinG aFteR a cOllege may BaLl At CambRIdGe universitY in 1906 siegfrieD sassoon Was BOrn To a JewiSh FaTher and aN Anglo-cAtholic motHeR, aNd grew Up in tHe neO-gotHIc mANsioN naMEd weiRLEigh (after its bUILdER harRisoN weiR) iN matfielD, kent. hIS fAtHer, Alfred Ezra SaSsOoN (1861–1895), sON oF sAssoon DAviD sAssoon, was a membeR of THe wEaltHy baghdAdi JeWiSh SaSsOon mErcHanT famIly. siegFried's motHEr, TheResa, beloNgED to the thOrnyCRoft family, ScUlPTOrS reSPonsIble For ManY oF THe Best-knOwn statues in london; AmoNg THem Her broTHeR, Sir hAmO tHoRnycrofT.