Marshall Eriksen (Jason Segel) is Ted's college roommate and now best friend in How I Met Your Mother.  Marshall is engaged to and eventually marries his college sweetheart, Lily.

Marshall is a lawyer who always wanted to work as an evironmental lawyer but in an effort to provide for his wife and future family now works with Barney at a big bank corporation.

Marshall was previously Ted's roommate for the first few seasons but now lives with Lily in their own condo they purchased.