BTD may refer to:

• Back to December, A song by American singer-songwriter Taylor Swift from her 3rd studio album Speak Now.
• BTD (Before the Dawn)
• Bloons Tower Defense, the tower defense series by Ninja Kiwi.
• Biotinidase, the enzyme that in humans is encoded by the BTD gene.
• British trade dollar, a silver coin minted by Great Britain to facilitate trade with the Far East.
• Douglas BTD Destroyer, 1940s American torpedo/dive-bomber.
• Built to Destroy (Michael Schenker Group album), the fourth album by the Michael Schenker Group
• Built to Destroy (Incite album), the fifth album by Incite