Invisibility is an ability that can be used to hide or conceal one's physical complexion.
- Graham Garrett, also known as the Chameleon, is an assassin, with the ability to make himself invisible. Clark's x-ray vision can't detect him. Genetic strands from Garrett was also used to give Wes Keenan invisibility as part of Project Ares.
- Jeff Palmer, after coming in contact with kryptonite-engrossed plants that grew around the Luthor Mansion's garden, gained the ability to make himself invisible using their oils. He scared Victoria Hardwick. Even now, it is remains unknown if these roses are still there, or if Lex Luthor is aware of the roses' power.
- John Jones can turn himself invisible, allowing him to sneak up on people. 
- Clark Kent could not see through Graham Garrett's invisibility with his X-ray vision, but Clark could see through Jeff Palmer. Therefore, this is another proof of the invisibility Lex Luthor used in Project Ares for Wes Keenan was Graham's, because Clark couldn't see through Wes Keenan with his X-ray visison.
In the Comics
Martian Manhunter is extremely talented in rendering himself invisible, by causing the bio-polymers in his body to lose their ability to reflect light, making him invisible to normal light and human sight. With excessive concentration, he can render himself completely invisible along the electromagnetic spectrum, including the infrared and the ultraviolet ranges of the spectrum. This invisibility does not affect every other sense and he could still be detected by touch.