sIG 33(德語:schweres Infanterie Geschütz 33,重步兵炮33年式)是納粹德國在二戰時期的步兵支援火炮,實際口徑149.1毫米,也是納粹德軍步兵科使用之最大口徑支援火器,主要用於壓制據點。標準的德軍步兵团會配發2門作為攻堅火力,由於為步兵單位設計,射程較短,後來為了因應機械化作戰節奏等需求,因此出現車裝版本,但基本設計從1933年後就沒有重要變化。
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