Oliver Lambart, 1st Baron Lambart

Oliver Lambart, 1st Lord Lambart, Baron of Cavan (died June 1618) was a military commander and an MP in the Irish House of Commons. He was Governor of Connaught in 1601. He was invested as a Privy Counsellor (Ireland) in 1603. He was also an English MP, for Southampton 1597. He is buried in Westminster Abbey.

Military
Fighting the Spanish, Lambert took part in the Dutch campaign under his commander Francis Vere: he was wounded in the assault on Steenwijk which led to its capture in 1592. On 20 June 1596, Essex and Effingham sacked the harbour of Cádiz. The Spanish scuttled their Indies fleet including a cargo of 12 million ducats. The force occupied the city until 5 July. Lambart was knighted for his part in the looting.

During the Nine Years' War (1594–1603) Lambart served in Essex's Irish campaign of 1599. He commanded the 200 Foot at Enniscorthy, County Wexford.

On 6 January 1615, he retook Dunyvaig Castle, Islay, with the assistance of Sir John Campbell of Calder.

Politics
He was in 1613 elected one of two MPs for County Cavan, sitting from 1613 to 1615. He was created 1st Lord Lambert, Baron of Cavan, County Cavan shortly before his death.

Family
His son was Charles Lambart, 1st Earl of Cavan.