A famous London physician, whose name appears in a number of the novels.

He was called in as a consultant in the illness of Bishop Grantly and of Dean Trefoil in Barchester Towers; of Sir Roger Scatcherd and Lady Augusta Gresham in Doctor Thorne; the old Duke of Omnium in The Prime Minister; George Bertram, Sr., in The Bertrams 41; and briefly when Lady de Courcy suggested an appeal to him to send her husband to a German spa in The Small House at Allington.

There is one reference to him in Doctor Thorne as "Sir Simon Omicron."