Ellen McLain is an opera singer and voice actress from Nashville, Tennessee, USA. McLain provides voices for many characters in several video games from Valve. Among them are GLaDOS, the artificial intelligence antagonist in Portal (for which she won an AIAS Interactive Achievement Award for Outstanding Achievement in Character Performance), the announcer in Team Fortress 2, and the voice of the Combine overwatch for the Half-Life 2 series.

She is currently the only person to have her voice in all the games in The Orange Box.

McLain also sang the ending credits song to Portal, titled "Still Alive", written by Jonathan Coulton.
She is married to John Patrick Lowrie, a fellow voice actor, who has also worked on the video game Half Life 2. Ellen voiced the antagonistic Overwatch voice, while her husband voiced a citizen that assists the protagonist.