The Bible doesn't specifically speak of "guardian angels."  It does speak of other types of angels however; such  as cherubim etc.  

Jesus, when speaking of children, said, "See that you do not look down on one of these little ones.  For I tell you that their angels in heaven always see the face of My Father in heaven."¹  From this verse, and other verses in the Bible (such, as, Psalm 91:11-12 and Hebrews 1:14), there is the belief that there are angels assigned to protect us.  The Bible doesn't speak of a specific group of angels known as "guardian angels" however.

Bible References:

¹ (Matthew 18:10)