六氧化二氯是一种无机化合物，化学式为Cl₂O₆。这种氯氧化物是氯酸和高氯酸的混合酸酐。

它可以由二氧化氯与过量的臭氧反应制得：

也可用氯气与臭氧在光照下直接反应，或者光解二氧化氯以及热分解高氯酸氯制得。

纯净的六氧化二氯由高氯酸氙分解获得：

Dichlorine hexoxide is the chemical compound with the molecular formula Cl
2O
6, which is correct for its gaseous state. However, in liquid or solid form, this chlorine oxide ionizes into the dark red ionic compound chloryl perchlorate [ClO
2]+[ClO
4]−, which may be thought of as the mixed anhydride of chloric and perchloric acids.