|Portrayed by||Christopher Gehrman|
|First appearance||The Beautiful Girls|
|Employer||Fillmore Auto Parts|
|Sibling(s)|| Leonard Fillmore|
Sean Fillmore is Fillmore Auto Parts executive.
Megan Calvet interrupted the meeting twice, to tell Don his daughter is in the office, to tell him that his secretary, Ida Blankenship has died. Don's help is requested, so he excuses himself from a meeting to help deal with the situation. Don returned, and had to stall the meeting from adjourning while the body of Ida Blankenship was moved by Joan and Pete. ("The Beautiful Girls")