Csvkit is a toolbox of command-line utilities for manipulating data in CSV format, which the csvkit authors describe as "the king of tabular data." It includes tools to ingest data from a variety of sources in several formats and generate well-formatted CSVs, tools to filter and subset data stored in CSV files, tools to produce summary statistics of a CSV file, and tools to export CSV data into other common formats. In the Tutorial section of the csvkit site users will find a series of example analyses based on widely cited public datasets. Detailed usage documentation for each csvkit tool can be located in the Reference section of the site. Csvkit is free software, distributed under the MIT license, with source code available on GitHub. Csvkit is written in Python and runs on Windows, macOS, and UNIX-like systems. Users can install csvkit either using their OS package manager or using Python's `pip`.