A toolkit is an assembly of tools; set of basic building units for user interfaces.

The word toolkit may refer to:

• Abstract Window Toolkit
• Accessibility Toolkit
• Adventure Game Toolkit
• B-Toolkit
• Cheminformatics toolkits
• Dojo Toolkit
• Fox toolkit
• GTK, the GIMP Toolkit
• Google Web Toolkit (GWT)
• Harmony (toolkit), an incomplete set of software widgets
• Helsinki Finite-State Technology (HFST)
• Insight Segmentation and Registration Toolkit
• IT Mill Toolkit
• Molecular Modelling Toolkit
• Multidimensional hierarchical toolkit
• Sun Java Wireless Toolkit
• OCR SDK, OCR Toolkit
• OpenGL Utility Toolkit (GLUT)
• Open Inventor 3D graphics API
• Qt
• Motif
• Natural Language Toolkit
• Portable, Extensible Toolkit for Scientific Computation
• Scedu Tender Readiness Toolkit
• Standard Widget Toolkit (SWT)
• Synthesis Toolkit
• Template Toolkit
• The Coroner's Toolkit, computer programs for digital forensic analysis
• User Interface Toolkit (UIM)
• X Toolkit Intrinsics