We present a new four‐parameter model of the D‐region (60–90 km) ionospheric electron density, useful in very low frequency (VLF, 3–30 kHz) remote sensing. VLF waves have a long history of use to indirectly infer D‐region conditions, as they reflect efficiently and thus are sensitive to small changes in the electron density. Most historical efforts use VLF observations along with a forward model of the D‐region and VLF propagation. The ionospheric assumptions in the forward model are altered until the output matches the observation. The most common D‐region model, known as the Wait‐Spies ionosphere, takes the electron density as exponentially increasing with altitude and specifies a height and steepness. This model was designed to capture the VLF propagation variations evident at a single frequency. The real D‐region is likely more complex. The limited number of D‐region rocket passes that have previously been compiled tend to show the existence of a “ledge” somewhere between 70 and 90 km. Broadband VLF signals emitted from lightning allows a more sophisticated parametrization. Using carefully averaged amplitudes and phases of VLF sferics, we formulate a more general four‐parameter D‐region model that includes a ledge discontinuity. Using lightning‐emitted VLF observations along with a theoretical model, we find that this model better describes the ionosphere during the daytime. During the ambient nighttime and during a solar flare the two‐parameter ionosphere may be sufficient, at least for the purposes of calculating broadband VLF propagation, since the ledge either weakens or moves outside the altitude range of VLF sensitivity. Plain Language Summary The Earth's ionosphere can be thought of as the border zone between Earth's atmosphere and space environment, between 60 and 1,000 km altitude. In this region, the thinning air is electrically charged by radiation from the sun, among other things, creating many free electrons. The ionosphere is important because, for example, it impacts several important forms of communication, both ground‐to‐ground and satellite‐to‐ground. The lowest part of the ionosphere is called the D‐region 60–90 km, and it is particularly tough to measure. For decades, researchers have fit a line to describe the number of electrons in the D‐region as a function of altitude. Fitting a line is not so good but it is often the best we can do since we have so little information. It is probably not very close to reality. By using untapped information contained in the radio emissions from lightning, which propagate in the VLF band (3–30 kHz) many thousands of kilomerter, we are able to describe the D‐region conditions with a more complicated shape that is closer to the physical reality. Key Points A new four‐parameter model of D‐region ionospheric electron density is introduced to better capture the D‐region ledge With this model, VLF remote sensing with broadband lightning sferics detect the depth and location of the ledge during the daytime During a solar flares and at nighttime, the ledge either dissipates or falls outside the altitude range of VLF sensitivity