Taddeo Barberini (1603–1647) was an Italian nobleman of the House of Barberini who became Prince of Palestrina and Gonfalonier of the Church; commander of the Papal Army. He was a nephew of Pope Urban VIII and brother of Cardinals Francesco Barberini and Antonio Barberini. Thanks to their uncle's famous nepotism, the brothers shaped 17th-century Italian politics, religion, art, music and architecture.

Barberini was born in 1603, the son of Carlo Barberini and Costanza Magalotti. He was the nephew of brothers cardinal Maffeo Barberini (later Pope Urban VIII) and Antonio Marcello Barberini (later also Cardinal) and of Lorenzo Magalotti. He was the brother of Francesco Barberini and Antonio Barberini, both of whom became Cardinals when their uncle became pope. Like his brothers, Taddeo was educated at the Collegio Romano.

In 1623, Maffeo Barberini was elected as Pope Urban VIII and Taddeo Barberini's fortunes improved considerably. Almost immediately, Barberini was appointed Gonfalonier of the Church; Commander of the Papal Army, though during later conflicts his brother Cardinal Antonio Barberini also commanded papal and mercenary troops in the field.

In 1624, Taddeo took control of the Duchy of Urbino, relinquished to Urban VIII after the death of Federico Ubaldo. When Francesco Maria died in 1631, the duchy was transferred to the Papal States.

On 14 October 1627 Barberini married Anna Colonna, daughter of Filippo I Colonna, at a lavish service presided over by the pope himself at the Castel Gandolfo. The agreement drawn up by Cardinal Fabrizio Verospi between the Barberini and Colonnas stipulated a dowry worth some 180,000 scudi which included cash and credit as well as a Colonna castle in Anticoli. It is thought the transfer of the Palestrina comune between the two families was tied to the agreement; part of Anna Colonna's dowry. Upon transfer, the commune became a fief of the Barberini which allowed the family to appoint one of its number as Prince of Palestrina, a title which was passed from one Barberini patriarch to another while the comune remained among family possessions. Taddeo's son Carlo Barberini later renounced his right to inherit his father's titles (as he would have done as eldest son) to become a cardinal. Taddeo's hereditary titles therefore passed to his second son, Maffeo.

As Prince of Palestrina, Taddeo worked to improve local buildings and establish new services, even if many of them were primarily self-serving. He rebuilt the Palazzo Barberini (which still houses the Nile mosaic of Palestrina) and his son Maffeo later commissioned a new church nearby. Taddeo built a small private casino which operated for a few years during his administration but closed when future princes had no interest in gambling.

Pope Urban further honoured his nephew in 1631 by appointing him Governor of the Borgo, Commander of Sant'Angelo and Prefect of Rome. Taddeo's investiture as prefect was celebrated with much pomp and extravagance.

It is estimated that by 1632, Taddeo's property was worth as much as 4 million scudi and that over the course of Urban VIII's 21-year reign, Taddeo amassed 42 million scudi in personal wealth. By 1635, income from Taddeo's property was estimated at 100,000 scudi per year.