There are a total of 133 8-letter words containing 'yo', and the number may vary in different dictionaries. You can specify the dictionary and order.

• alleyoop ₁₅
• baryonic ₁₇
• bayonets ₁₄
• botryoid ₁₄
• botryose ₁₃
• bryology ₁₈
• bryonies ₁₄
• bryozoan ₂₃
• carryons ₁₄
• carryout ₁₄
• caryotin ₁₄
• chayotes ₁₅
• conveyor ₁₈
• crayoned ₁₅
• cryogens ₁₆
• cryogeny ₁₈
• cryolite ₁₄
• cryonics ₁₇
• cryostat ₁₃
• cryotron ₁₄
• disyoked ₁₆
• disyokes ₁₅
• embryoid ₁₇
• embryons ₁₇
• everyone ₁₅
• flyovers ₁₈
• grayouts ₁₃
• halcyons ₁₇
• hyoidean ₁₄
• hyoscine ₁₆
• hypopyon ₂₁
• joyously ₂₃
• karyotin ₁₅
• kryolite ₁₅
• kryolith ₁₇
• layovers ₁₅
• lyophile ₁₇
• mayoress ₁₃
• mirnyong ₁₇
• misyoked ₁₈
• misyokes ₁₇
• myoblast ₁₇
• myogenic ₁₉
• myograph ₂₀
• myologic ₁₉
• myomeres ₁₆
• myomorph ₂₁
• myopathy ₂₀
• myoscope ₁₉
• myositis ₁₃
• myosotes ₁₃
• myosotis ₁₃
• myotises ₁₃
• myotomes ₁₆
• myotonia ₁₄
• myotonic ₁₇
• playoffs ₂₀
• polyomas ₁₇
• purveyor ₁₈
• pyoderma ₁₇
• pyogenic ₁₉
• pyorrhea ₁₅
• rhyolite ₁₃
• sabayons ₁₄
• sayonara ₁₁
• surveyor ₁₅
• tachyons ₁₆
• tardyons ₁₂
• thankyou ₁₈
• unyoking ₁₉
• yobbiest ₁₆
• yodelers ₁₂
• yodeling ₁₅
• yodelled ₁₄
• yodeller ₁₃
• yogasana ₁₃
• yoghourt ₁₅
• yoghurts ₁₅
• yohimbes ₁₈
• yokeless ₁₅
• yokelish ₁₇
• yokemate ₁₇
• yokozuna ₂₅
• yolkiest ₁₅
• yolkless ₁₆
• youngers ₁₄
• youngest ₁₄
• youngish ₁₆
• youngman ₁₈
• youngmen ₁₈
• younkers ₁₆
• yourself ₁₅
• youthens ₁₄
• youthful ₁₈
• crayoner ₁₃
• cryobank ₁₉
• myosises ₁₃
• peyotism ₁₅
• yogourts ₁₂
• akaryote ₁₅
• billyohs ₁₆
• chanoyos ₁₆
• eucaryon ₁₃
• eucaryot ₁₃
• eukaryon ₁₅
• eukaryot ₁₅
• geomyoid ₁₅
• hallyons ₁₄
• kayoings ₁₆
• kurveyor ₁₈
• lyolyses ₁₄
• lyolysis ₁₄
• lyophobe ₁₈
• myograms ₁₆
• myomancy ₂₀
• myophily ₂₁
• myotubes ₁₅
• omohyoid ₁₇
• peyotist ₁₃
• polyonym ₁₈
• pyonings ₁₄
• ryotwari ₁₄
• talayots ₁₁
• unjoyous ₁₈
• yobbisms ₁₇
• yoicking ₁₈
• yoicksed ₁₈
• yoickses ₁₇
• yoldring ₁₃
• yonderly ₁₅
• youngths ₁₅
• youthier ₁₄
• yowlings ₁₅

There are 133 8-letter words containing yo in the well-known word game dictionary, 91 in the Scrabble US (US/Canada/Thailand - TWL/NWL) dictionary, and 122 in the Scrabble UK (International - SOWPODS/CSW) dictionary, and 94 in the Words with Friends (WWF) dictionary.