Jack Sinclair may refer to:
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Jack Sinclair (footballer) (born 1995), Australian rules footballer for St Kilda
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Jack Sinclair (Scouting) (fl. 2004), president and international commissioner of Scouts Canada
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Jack Sinclair (poker player) (born 1990), English professional poker player
See also
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John Sinclair (disambiguation)
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Jonathan Sinclair (disambiguation)
{{hndis, Sinclair, Jack