Allem was born in Kroonstad, Orange Free State, South Africa,[2] the middle child of five children and the grandson of a Lebanese trader; he had a privileged upbringing.

By the time he came into the world, his family had the largest corn farm in the Southern Hemisphere and the only privately owned grain silos in South Africa.

A second-place finish in the 1987 NEC World Series of Golf convinced him to join the PGA Tour.

He won the Southwestern Bell Colonial and NEC World Series of Golf that year, two of the Tour's most prestigious non-majors.

[4] His youngest brother is the interior designer Charles Allem, Principal of CAD International based in Miami.