David William Sims (born September 17, 1963) is an American musician, best known as the bass guitarist of the bands Scratch Acid (with whom he initially played guitar), Rapeman, and The Jesus Lizard.

He has also recorded or performed with Sparklehorse, Rhys Chatham, Shivaree, Pigface, Flour, and others.

Sims currently performs experimental solo electric bass as Unfact.

[1] Besides being a musician, Sims is a Certified Public Accountant[2] and blogged on his personal website from 2008 to 2011, with only updates subsequently.

In a Kreative Kontrol podcast in 2014, it was discussed that Sims "always had issues with the name" of Rapeman and that it was "the biggest musical regret" of his life.