Class 44 may refer to:

• British Rail Class 44, a British Railways/British Rail diesel locomotive type
• DRG Class 44, a Deutsche Reichsbahn German steam locomotive type

• Obregón City
• Obren Joksimović
• Obrenovac (Belgrade)
• Obrenovac Municipality
• Obrenovi
• Obrenovich
• Obrenović
• Obrenović Dynasty
• Obrenović family tree
• Obren Petrovic
• Obren Petrović
• Obreption
• Obreption and subreption
• Obreption and Subreption
• Obreros Unidos
• Obrestad
• Obretenov
• Obretenova
• Obrez
• Obrež
• Obrești River
• Obri
• O'Brian
• Obriareos
• O'Brien baronets