Helen McGregor may refer to:

• Helen McGregor (writer), writer, actor and lecturer
• Helen McGregor (geologist) (born 1974), Australian geologist and climate change researcher

• Nucleon spin structure
• Nucleon (Transformers)
• Nucleo Operativo Centrale di Sicurezza (NOCS)
• Nucleophic carbene
• Nucleophilic acyl substitution
• Nucleophilic aliphatic substitution
• Nucleophilic conjugate addition
• Nucleophilic displacement
• Nucleophillic addition
• Nucleophosmin
• Nucleophyl
• Nucleoplasty
• Nucleopore
• Nucleopore filter
• Nucleopore membrane
• Nucleoporin
• Nucleoporin 153
• Nucleoporin 210kDa
• Nucleoporin 62
• Nucleoporins
• Nucleoproteins
• Nucleoside analogue
• Nucleoside analogue reverse transcriptase inhibitor
• Nucleoside analogue reverse transcriptase inhibitors
• Nucleoside phosphoramidite