The legislative branch of ASUCD is headed by the ASUCD Senate.  Under it is a large support network containing seven commissions, various committees, and the Outreach Assembly.  The legislative branch is an excellent way for people interested in ASUCD government to get a foot in the door and experience its operations first hand.  Many students begin their ASUCD career interning for a Senator or serving in a commission.

The ASUCD Senate is the body which introduces, and commonly writes, legislation.  Once legislation is submitted to the Senate it gets referred to any number of the relevant commissions to scrutinize the legislation and offer their specialized opinion on it. Various committees also exist to serve specific functions, such as the Elections Committee to run elections.