Carlo Alfredo Piatti (January 8, 1822 – July 18, 1901) was an Italian cellist, teacher and composer.
Piatti was born at via Borgo Canale, in Bergamo and died in Mozzo, 4 miles from Bergamo.

The son of a violinist, Antonio Piatti, he originally began his studies on the violin before switching to the cello. As a cellist, he studied under his great-uncle, Gaetano Zanetti, a great cellist. After two years of studying, he joined the theater orchestra, where he played for three months - for ten shillings, half of which his grandfather took. After Zanetti's death, he became a pupil at the conservatorio of Milan under Vincenzo Merighi. He made his concert debut at 15 and started touring at 16. No one doubted the young virtuoso's skill on the instrument, but he did not draw large crowds. As a result, when Piatti fell ill during an engagement, he was forced to sell his cello to cover the medical costs. Franz Liszt invited him to appear as a guest performer at one of his recitals; stunned by what the boy could do on a borrowed cello, Liszt presented him with a superb new instrument. Piatti went on to become one of the most celebrated cellists of his day, as popular for the pieces he wrote as for the robust and unsentimental way he performed them.

From 1838, he journeyed over Europe, playing with extraordinary success in all the important cities of the continent. In 1844 he appeared before the London public at a Philharmonic Concert.

In 1852 he premiered (and became the dedicatee) of a Sonata Duo for cello and piano, Op. 32, by William Sterndale Bennett, having been given the original manuscript of the music in the morning, studied it on a train then played it at the concert that same evening with the composer as pianist playing from memory.

In 1859, on the foundation of the Popular Concerts, he took up the work with which he was most intimately connected for thirty-nine seasons. He retained until 1897 the post of first cello at these famous chamber concerts, during the latter half of each series. He played a Stradivarius which now is named after him Piatti and is owned by the Mexican cellist Carlos Prieto.

He composed two cello concertos, one cello concertino, six cello sonatas, lieder for voice and cello accompaniment, and cello solos, as well as a cello method.

His pupils were many, and included Robert Hausmann.