Randall's career began at Chez Max in Surbiton, London, where he trained in classical cooking for four years.

[1] After a year he moved to California to work at Chez Panisse under chef Alice Waters for 12 months.

[1][2] He then returned to the UK where he spent fifteen years, ten of which were as Head Chef and silent partner back at The River Café where he gained his Michelin star.

Theo Randall at the InterContinental London opened in February 2007 as part of a £60 million refurbishment of the hotel.

[9] In 2010, Randall started working with ASK Italian restaurants as their "expert friend", developing menus and coming up with new dishes.