黑线鳕（学名：Melanogrammus aeglefinus）是鳕形目鳕科黑线鳕属的一种鱼类，被IUCN列为次级保育类动物，产于北大西洋，从比斯开湾至巴伦支海等海域，栖息深度10-450公尺。本鱼口相对较小；下颌比上颌短下巴触须相当小，鳞片重叠，大暗斑是胸鳍正下方的侧线以上，因黑色的侧线而得名，体长可达69公分。栖息在沙石底质的海域，为底栖性鱼类，属肉食性，以鱼类、甲壳类、头足类、棘皮动物等为食，是一种名贵的食用鱼，适合各种烹饪方式食用。

《独角兽号的秘密》中，阿道克家族的马林斯派克大厅的门柱上，雕刻了一条黑线鳕。

The haddock (Melanogrammus aeglefinus) is a salt water fish, found in the North Atlantic Ocean and associated seas.

The haddock is easily recognized by a black lateral line running along its white side (not to be confused with pollock which has the reverse, i.e., white line on black side) and a distinctive dark blotch above the pectoral fin, often described as a "thumbprint" or even the "Devil's thumbprint" or "St. Peter's mark".