Combe Sydenham is a 15th-century manor house south of Monksilver in the parish of Stogumber, Somerset, England. It has been designated as a Grade I listed building.
Combe Sydenham is mentioned as a manor belonging to William de Moyon in the Domesday Book in 1086.
The porch was added in 1580 to the south front of the building. The west front was refenestrated, and at least 2 stair turrets added in the late 16th or early 17th century. The south front has been refenestrated and buildings to the north and east were demolished.
Combe Sydenham Hall was the home of the Sydenham family from the fourteen hundreds to the mid 18th century.
In 1585, Francis Drake married Elizabeth Sydenham—born circa 1562, the only child of Sir George Sydenham, who was the High Sheriff of Somerset. Drake and Elizabeth Sydenham were to be married earlier however he left on a long voyage and her father arranged for her to be married to a son of the Wyndham family of Orchard Wyndham. On the day of wedding as they were approaching the Church of St Mary at Stogumber there was a loud clap of thunder and a large meteorite crashed through the roof. This was seen as a bad omen and the wedding stopped. Drake had arrived back in Plymouth the same day, and they were later married at the Church of All Saints in Monksilver. The iron meteorite, which became known as "Drake's cannon ball", is 14 inches (36 cm) in diameter. It has been polished when rolled down hills and has remained at the house ever since. After Drake's death, Elizabeth eventually married Sir William Courtenay of Powderham.
The house is set in a 500 acres (202.3 ha) estate which offers a Deer Park and a variety of walks.