<p>The ability to precisely focus optical beams is crucial for numerous applications, including imaging. The slow intensity transitions of conventional Gaussian beams near the focal point limit their effectiveness in scenarios requiring sharp focusing. Ultrafast self-focusing of circular Airy beams has been reported in two dimensions. Here we demonstrate this capability for spherical Airy wavepackets, a three-dimensional light field with an Airy function distribution in the radial direction. We sculpt spherical Airy wavepackets to exhibit ultrafast self-focusing with a substantially reduced depth of focus, compared with both conventional Gaussian beams and circular Airy beams. Our measurements confirm the wavepacket’s nonlinear intensity increase and tight spatiotemporal confinement. The superior focusing dynamics of spherical Airy wavepackets are broadly applicable to high-resolution imaging, nonlinear optics and optical trapping. Overcoming current limitations from pixelated modulation devices, such as spatial light modulators, could further enhance focusing performance, paving the way for advanced applications in biomedical imaging, laser processing and ultrafast optics.</p>