LIRS may refer to:

• Local Internet registries
• Last modified Information Relaying Specification a Web feed formats

• Muddguts
• Mud Digger
• Muddilake Brook
• Muddiman, Alexander
• Muddle Earth (John Brunner)
• Muddle (Kent cricketer)
• Muddling Through in Madagascar
• Mud Duck Productions
• Muddula Koduku
• Muddula Koduku (1979 film)
• Muddula Mogadu (1983 film)
• Muddula Mogudu (1983 film)
• Muddus Plains
• Muddy Bubbles Hell
• Muddy Creek Archeological Complex
• Muddy Creek (Cass County, Missouri)
• Muddy Creek (Conestoga River)
• Muddy Creek (Daviess County, Missouri)
• Muddy Creek (Grand River)
• Muddy Creek (Lamine River)
• Muddy Creek (Lane County, Oregon)
• Muddy Creek (Little Miami River)
• Muddy Creek (Missouri)
• Muddy Creek (Nodaway River)
• Muddy Creek (Slippery Rock Creek)