Frank Loder was a recurring antagonist from the WB TV series Smallville making several appearances in Season 3. He was an FBI agent on the payroll of the Luthors.
He was portrayed by Gary Hudson.
Loder was an FBI agent who was contacted by Lex Luthor originally to help him get the charges dropped against him for the murders committed by Adam Knight at Metron Pharmaceuticals. In exchange for this favor, Lex agreed to help Loder try and take down Lex's father Lionel. Loder established surveillance on Lionel keeping track of his every move.
Lex later consults with Agent Frank Loder and tells him to disregard Lionel's comments about the Kents, saying that he only agreed to help them bring Lionel down and to not interfere with the Kents. Loder was dubious at Lex's insistence that Clark is an ordinary boy. Lex went to Frank Loder who explained that the FBI was not interested in the Kents.
Loder seemed to be working for Lionel as well when he contacted him informing Luthor that Lex didn't have any evidence against Lionel, but if he does it will stay buried, and that he will look into the Ross kid while holding a file on Clark Kent. Pete was driving home when Loder pulls him over, saying he has to ask some questions about his mother's federal judgeship. He took Pete to a dock and beats him up while demanding to learn Clark Kent's secret, assuming that Clark's best friend must know it. Lex arrived just in time to pull Loder off, revealing that Lionel paid him off to drop the case and investigate Clark instead. Lex ordered him to get back to Lionel's case and gave him a transcript of Lionel's voicemail confession. Loder backs off, but remarked that Pete was keeping a secret bigger than Lionel. Lex later went to Lionel's office again and asked Lionel about Emily Dinsmore. He was soon followed by Loder and other federal agents, who arrest Lionel for the murder of his parents and was ushered away in handcuffs.
Even in jail, Lionel expected him to continue investigating Clark.