China 
Africa 
- Soybean mosaic virus
- Soybean oil
- Soybeans
- Space filling model
- Space medicine
- Space of disse
- Spacer DNA
- Spacing effect
- Spanish influenza
- Sparfloxacin
- Sparganosis
- Spartalizumab
- Sparteine
- Spas
- Spasm of accommodation
- Spasmodic dysphonia
- Spasmodic torticollis
- Spasms
- Spastic cerebral palsy
- Spastic diplegia
- Spastic hemiplegia
- Spastic paraplegia
- Spastic paresis
- Spastic quadriplegia
- Spasticity
- Spathulenol
- Spatial ability
- Spatial cognition
- Spatial disorientation
- Spatial epidemiology
- Spatial learning
- Spatial light modulators
- Spatial memory
- Spatial neglect
- Spatial normalization
- Spatial orientation
- Spatial statistics
- Spatial summation
- Speaker recognition
- Spearman's rank correlation coefficient
- Special senses
- Specialized pro-resolving mediators
- Specialty pharmacy
- Species complex
- Species extinction
- Specific Absorption Rate
- Specific Dynamic Action
- Specific appetite
- Specific developmental disorder
- Specific granules
- Specific gravity
- Specific inhalation challenge
- Specific phobia
- Specific rotation
- Specific-pathogen-free
- Specificity constant
- Specificity factor
- Specimen
- Speciociliatine
- Speckle tracking echocardiography
- Spectinomycin
- Spectral imaging
- Spectral radiance
- Spectral reflectance
- Spectral sensitivity
- Spectralon
- Spectrin
- Spectrin repeat
- Spectrofluorometer
- Spectrometry
- Spectrophotometers
- Spectrophotometry
- Spectroscopy
- Spectrum analysis
- Spectrum bias
- Spectrum disorder
- Speech Transmission Index
- Speech and language impairment
- Speech banana
- Speech disorders
- Speech errors
- Speech impediment
- Speech perception
- Speech repetition
- Speech synthesis
- Speech therapy
- Speech-generating device
- Speech-language pathology
- Speedball
- Sperm
- Sperm banks
- Sperm competition
- Sperm count
- Sperm donation
- Sperm granuloma
- Sperm motility
- Sperm sorting
- Sperm storage
- Sperm washing
- Spermarche
- Spermatheca
- Spermatic
- Spermatic cord
- Spermatids
- Spermatocele
- Spermatocytes
- Spermatocytogenesis
- Spermatogenesis
- Spermatogonia
- Spermatogonial stem cells
- Spermatophores
- Spermatorrhea
- Spermatozoa
- Spermaturia
- Spermicide
- Spermidine
- Spermine
- Spermiogenesis
- Sphaerotilus natans
- Sphenoethmoidal recess
- Sphenoethmoidal suture
- Sphenoid
- Sphenoid bone
- Sphenoid sinus
- Sphenoid wing meningioma
- Sphenoidal sinus
- Sphenomandibular ligament
- Sphenopalatine artery
- Sphenopalatine foramen
- Sphenoparietal sinus
- Sphenozygomatic suture
- Spherical aberration
- Spherical design
- Spherocytosis
- Spheroplasts
- Sphincter
- Sphincter of Oddi
- Sphincter of Oddi dysfunction
- Sphincter pupillae muscle
- Sphincterotomy
- Sphincters
- Sphingobium
- Sphingolipidoses
- Sphingolipids
- Sphingomonas elodea
- Sphingomyelin
- Sphingomyelin phosphodiesterase
- Sphingomyelinase
- Sphingomyelinase D
- Sphingosine