There are a total of 65 9-letter words containing 'box', and the number may vary in different dictionaries. You can specify the dictionary and order.

• bandboxes ₂₄
• beatboxed ₂₃
• beatboxer ₂₂
• beatboxes ₂₂
• boomboxes ₂₅
• boxboards ₂₃
• boxelders ₂₁
• boxercise ₂₂
• boxfishes ₂₄
• boxhauled ₂₄
• boxscores ₂₂
• boxspring ₂₅
• boxthorns ₂₂
• callboxes ₂₄
• carboxies ₂₂
• carboxyls ₂₅
• cashboxes ₂₄
• coalboxes ₂₃
• coolboxes ₂₃
• feedboxes ₂₃
• fireboxes ₂₂
• fuseboxes ₂₃
• fuzzboxes ₄₁
• gearboxes ₂₁
• gogglebox ₂₆
• hellboxes ₂₃
• homoeobox ₂₄
• jukeboxes ₃₃
• kickboxer ₃₀
• letterbox ₂₀
• listboxes ₂₀
• lockboxes ₂₇
• mailboxes ₂₃
• nestboxes ₂₀
• outboxing ₂₃
• pepperbox ₂₈
• pillarbox ₂₄
• pillboxes ₂₄
• postboxes ₂₂
• rattlebox ₂₀
• saltboxes ₂₀
• sandboxes ₂₁
• shadowbox ₂₅
• shoeboxes ₂₁
• signalbox ₂₃
• soapboxes ₂₂
• strongbox ₂₂
• suboxides ₂₁
• tickboxes ₂₆
• tinderbox ₂₁
• toolboxes ₂₀
• windowbox ₂₇
• woodboxes ₂₃
• workboxes ₂₆
• cakeboxes ₂₄
• fareboxes ₂₁
• kickboxed ₂₉
• kickboxes ₂₈
• soapboxed ₂₁
• boxkeeper ₂₄
• boxwallah ₂₄
• seedboxes ₁₉
• showboxes ₂₄
• talkboxes ₂₂
• tuckerbox ₂₄

There are 65 9-letter words containing box in the well-known word game dictionary, 43 in the Scrabble US (US/Canada/Thailand - TWL/NWL) dictionary, and 48 in the Scrabble UK (International - SOWPODS/CSW) dictionary, and 54 in the Words with Friends (WWF) dictionary.