G45 may refer to:

• List of Intel chipsets#Core 2 chipsets
• HMS Quail (G45)
• G45 Daqing–Guangzhou Expressway in China

• ThiemeWorks
• Thieme Works
• Thieme–Becker
• Thiemo-Jerome Kialka
• Thiemo-Jérome Kialka
• Thiemo-Jérôme Kialka
• Thiemo Kialka
• Thienalprazolam
• Thien Duong Cave
• Thiene Cathedral
• Thien Hau
• Thienhaus v Metje & Ziegler
• Thien Hau Temple, Ho Chi Minh City
• Thien LE
• Thien menh anh hung
• Thien Minh Ly
• Thien Mu Pagoda
• Thien Nguyen
• Thien Nguyen (soccer)
• Thienodiazepines
• Thienorphine
• Thien Truong Stadium
• Thien tu
• Thien uyen tap anh
• Thienyl