Robert de Beaumont, 1st Earl of Leicester and Count of Meulan (1050 – June 5, 1118) was a powerful English and French nobleman, revered as one of the wisest men of his age. Chroniclers speak highly of his eloquence, his learning, and three kings of England valued his counsel.

He was the eldest son of Roger de Beaumont and Adeline of Meulan, daughter of Waleran III, Count de Meulan, and an older brother of Henry de Beaumont, 1st Earl of Warwick. He accompanied William the Conqueror to England in 1066, where his service earned him more than 91 lordships and manors. When his mother died in 1081, Robert inherited the title of Count of Meulan in Normandy, also the title of Viscount Ivry and Lord of Norton. He did homage to Philip I of France for these estates and sat as French Peer in the Parliament held at Poissy.

At the Battle of Hastings Robert was appointed leader of the infantry on the right wing of the army.
He and his brother Henry were members of the Royal hunting party in the New Forest, when William Rufus received his mysterious death wound, 2 August 1100. He then pledged alligience to William Rufus' brother, Henry I of England, who created him Earl of Leicester in 1107.

On the death of William Rufus, William, Count of Evreux and Ralph de Conches made an incursion into Robert's Norman estates, on the pretence that they had suffered injury through some advice that Robert had given to the King; their raid was very successful for they collected a vast booty.

In 1096 he married Isabella de Vermandois, daughter of Hugh Magnus and a scion of the French royal family.

According to Henry of Huntingdon, Robert died of shame after "a certain earl carried off the lady he had espoused, either by some intrigue or by force and stratagem." His wife Isabella remarried in 1118 to William de Warenne, 2nd Earl of Surrey.