Ashley Williams served on Eden Prime prior to the Geth attack, and following the event she joined Commander Shepard in hopes to stop Saren and his Geth. She is confident, independent, and at times, outright aggressive. Her grandfather served in the Alliance and surrendered to turian forces in the First Contact War; as a result she joined the military feeling like she had something to prove. At times her xenophobia can get the best of her and she can come across as insular and not willing to accept help when it is needed.

Following the rescue of the Citadel, Ashley remained with Commander Shepard on the Normandy as they scoured the galaxy eliminating the remaining Geth forces.