Mallory O'Brien is a fictional character on NBC's drama "The West Wing". The character is portrayed by Allison Smith. Mallory is the daughter of Leo McGarry, White House chief of staff and 2006 Democratic vice-presidential nominee, and his ex-wife, Jenny McGarry. She is an elementary school teacher, and a potential love interest of Sam Seaborn, deputy communications director for the Bartlet White House. In Season Two, she is cited to be dating a hockey player named Richard Andrewchuk, although they break up in Season Four following his being traded to Chicago.
Mallory is the only non-regular character to appear in both the first and last episodes of the series.
The extent of Mallory and Sam's relationship is never fully touched on. By Season Two, according to Sam, they've had nothing more than one date and some flirtation (which, as we see on screen, has included kissing). In Season Four, however, they are seen going home together implying a furtherance of their relationship by at least that point. They are not in the same episode together again until the series finale, by which time Mallory has an infant son and Sam is engaged. C.J. mentions to Mallory that Sam's back in town in case she wants to meet up with him, but Mallory makes a bit of a face (implying that it would be uncomfortable) and says no.