Charl (Sarel) Arnoldus Cilliers (1801 – 1871) was a Voortrekker leader and a preacher. With Andries Pretorius, he led the Boers to a huge victory over the Zulus at the Battle of Blood River in 1838. In particular, Cilliers lead the Voortrekkers in a vow which promised that if God would protect them and deliver the enemy into their hands, they would build a church and commemorate the day of their victory as if it were an annual Sabbath day, which their descendants would also be instructed to honour.
He was a prominent member of the Gereformeerde Kerk (Reformed Church), an offshoot of the Dutch Reformed Church. He is described as being a short, stout man, and was believed to have been very religious. He joined the Great Trek at the age of thirty-five.
The town of Kroonstad was, according to folklore, named after a horse belonging to Cilliers, which drowned in a stream (Kroonspruit) where the town is situated.
There is a Sarel Cilliers Museum as well as a statue of him (on the site of the Dutch Reformed Church) in Kroonstad. Numerous streets and roads in Kroonstad and throughout South Africa are named after him.
Sarel Cilliers was born the fourth of seven children in Schoongezicht, Cape Colony to Carel Cilliers and his wife, Elizabeth Catherine Louw. In 1806 his parents sold Schoongezicht, when Cilliers was five years of age.