Threlkeld is the surname of:

• Caleb Threlkeld (1676–1728), Irish botanist
• Dale Threlkeld, American artist
• Lancelot Edward Threlkeld (1788-1859), English missionary, primarily in Australia
• Oscar Threlkeld, English footballer, currently playing for Bolton Wanderers
• Richard Threlkeld (1937-2012), American television news correspondent

• Betanamin
• Beta-naphthol
• Beta-naphthylmethyl ether
• Betanase
• Betancourt v. Trinitas
• Betancuria Express
• Betanechol
• Betanecrovirus
• Beta-Neg
• Beta negative binomial distribution
• Beta Negative Binomial distribution
• Beta negative decay
• Beta-Neo-endorphin
• Betanese 5
• Beta News Agency
• Betani
• Betania
• Betania, Chiapas
• Betania (disambiguation)
• Betania monastery
• Betania, Panama
• Betania, Venezuela
• Betani Gharbi
• Betanis
• Beta-Nitropropionic acid