4th parallel may refer to:

• 4th parallel north, a circle of latitude in the Northern Hemisphere
• 4th parallel south, a circle of latitude in the Southern Hemisphere

• DM 95.5
• DMA-33
• DMA-66
• DMAC
• D-MAC
• Dmad
• D. madagascariensis
• Dma design
• DMADV
• DMAIC
• D Major
• D-major
• D-malate dehydrogenase (decarboxylating)
• DMA (magazine)
• DMA (Magazine)
• DMA members
• D-Man
• Dmanisi (paleoanthropology)
• Dmanisi Province, Ottoman Empire
• D-mannitol oxidase
• DMAPI
• DMarc
• DMARC
• D'Marco Farr
• D'marco Farr