|Saint John Powell|
|Portrayed by||Charles Shaughnessy|
|First appearance||The Jet Set|
|Final appearance||Shut the Door. Have a Seat|
|Employer||Puttnam, Powell, and Lowe|
Saint John Powell was the managing director of London-based advertising firm Puttnam, Powell, and Lowe.
Duck Phillips, believing that he was going to be let go from Sterling Cooper after a string of disappointments, met with Powell and Alec Martin to propose that Putnam Powell buy out Sterling Cooper. Powell convinced him to have a drink, either unaware or uncaring of Duck's drinking habit. Powell eventually made an offer that is acceptable to Duck.
After a year of beefing up sales and cutting down on personnel and costs, Saint John eventually plans to sell PP&L as well as Sterling Cooper to McCann Erickson. When Pryce finally learns of this, he discovers that after the sale that he was slated to be sent to India. Lane was convinced to free Don Draper, Bertram Cooper, and Roger Sterling from their employment contracts to start a new advertising agency. Lane made Saint John aware of this, sounding off a "Happy Christmas" after being fired by Saint John for "lack of character."