Jan Křtitel Kuchař, or also German: Johann Baptist Kucharz (March 5, 1751, Choteč - February 18, 1829, Prague) was a Czech organist, harpsichordist, music composer and teacher.

Soon after his birth, Kuchař's parents moved to Mlázovice, where he lived out his childhood. He achieved basic music knowledge in Vrchlabí with the organist Alex Thám. Later he studied at jesuit gymnasia in Hradec Králové and Jičín. He was a student of organist Josef Seger. From 1772 he acted as organist in the Kostel sv. Jindřicha v Praze (Church of St. Jindrich in Prague). In Prague, he also began teaching music in the noble Hartig, Buquoy and Příchovský families. He was active in the teaching of singing, piano and composition.

Kuchař was among the first to recognize the genius of W. A. Mozart and started to propagate it. In the year 1786, he most likely played in the Stavovské divadlo at the premiere of The Marriage of Figaro and in January 1787 he became acquainted with Mozart on his Prague visit. On October 28 in the same year, he played together with Mozart on harpsichord at the premiere performance of Don Giovanni. He wrote piano excerpts from both operas, as well as from the opera Così fan tutte. In addition, he composed recitatives for an Italian version of The Magic Flute.

In 1790, Kuchař left the church after being nominated as organist of the Monsastery at Strahov, in the Kostel Nanebevzetí Panny Marie (Church of the Assumption), on September 1. He also began to perform stand-alone concerts. The influence of Mozart, who in 1787 improvised on the Strahov organ, is perceptible in Kuchař's music and it also led Kuchař to Freemasonry in Prague. From 1791, he performed as harpsichordist of the Pražská operní společnost (Prague Opera Society). On September 6, 1791, he likely played at the premiere of Mozart's opera La clemenza di Tito. In this period he composed a series of organ and chamber compositions, especially for the Strahov choir.