铁氰化钾、六氰合铁(III)酸钾，是一种无机化合物，化学式为K₃[Fe(CN)₆]，俗称赤血盐。该亮红色固体盐含有[Fe(CN)₆]配离子。 它可溶于水，水溶液带有黄绿色荧光。

铁氰化钾是用氯气氧化亚铁氰化钾溶液制备的：

2K₄[Fe(CN)₆] + Cl₂ → 2K₃[Fe(CN)₆] + 2KCl

Potassium ferricyanide is the chemical compound with the formula K₃[Fe(CN)₆]. This bright red salt contains the octahedrally coordinated [Fe(CN)₆] ion. It is soluble in water and its solution shows some green-yellow fluorescence.