Brendan O'Brien may refer to:
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Brendan O'Brien (bishop) (born 1943), Roman Catholic archbishop of Kingston, Ontario, Canada
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Brendan O'Brien (cricketer) (born 1942), Irish former cricketer
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Brendan O'Brien (journalist), senior Irish journalist on RTÉ's ''Prime Time'' current affairs programme
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Brendan O'Brien (record producer) (born 1960), record producer, mixer, engineer, and musician
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Brendan O'Brien (screenwriter), American screenwriter
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Brendan O'Brien (voice actor) (1962–2023), actor and voice of many Crash Bandicoot characters
{{hndis, Obrien, Brendan