The Solar dynasty or Sūryavaṃśa (lit. 'Descendants of the Sun'; Sanskrit: सूर्यवंश), also called the Ikshvaku dynasty, is a lineage or dynasty said to have been founded by Ikshvaku. In Hindu literature, it ruled the Kosala Kingdom, with its capital at Ayodhya, and later at Shravasti. They worshipped their clan deity, Surya (a Hindu solar deity), after whom the dynasty is named. Along with the Lunar dynasty, the Solar dynasty comprises one of the main lineages in Hinduism.

According to Jain literature, the first Tirthankara of Jainism, Rishabhanatha himself, was King Ikshvaku. Twenty-one further Tirthankaras were born in this dynasty.

According to Buddhist literature, Gautama Buddha descended from this dynasty.

The important personalities belonging to this royal house are Mandhatri, Muchukunda, Ambarisha, Bharata, Bahubali, Harishchandra, Dilīpa, Sagara, Raghu, Dasharatha, Rama, and Pasenadi. Both the Hindu Puranas and the Buddhist texts include Shuddodhana, Gautama Buddha, and Rahula in their accounts of the Ikshvaku dynasty but, according to the Buddhist texts, Mahasammata, an ancestor of Ikshvaku who was elected by the people as the first king of the present era, was the founder of this dynasty.

Suryavamsha, or the Solar Dynasty, is one of the two major legendary Kshatriya dynasties found in Hindu Puranic and epic literature, the other being Chandravamsha or the Lunar dynasty. According to Harivamsa, Ikshvaku is considered the primogenitor of the dynasty of, and was granted the kingdom of Aryavarta by his father Vaivasvata Manu. Manu settled down in the Aryavarta region after he survived the great flood. A. K. Mozumdar states that Manu is the one who built a city on the Sarayu (being the river that his mother Sanjana was the goddess of) and called it Ayodhya meaning the 'invincible city'. This city served as the capital of many kings from the solar dynasty and is also believed to be the birthplace of Rama.

Some Hindu texts suggest Rishi Marichi, one of the seven sages and first human creations of Brahma as the progenitor of the dynasty. Marichi's eldest son Kashyapa is said to have settled down in Kashmir (Kashyapa-Meru or Kashyameru). He also contributed to the verses of the Vedas. Later, Vivasvan, son of Kashyapa and Aditi, famously known as the Hindu god Surya married Saranyu who was the daughter of Vishvakarman, the architect of devas. He had many children but Manu was given the responsibility of building the civilization and as a result it formed a dynasty that was named 'Suryavamsha' or the solar dynasty. Manu is also the progenitor of the Lunar Dynasty because he married his daughter Ila to Budha, the son of Chandra or the moon god and the couple gave birth to the magnanimous King Pururavas who became the first king of the Chandravamsha, or the Lunar dynasty.

After the death of the powerful king Prasenjit and disappearance of his successor Viḍūḍabha after defeating the Shakyas, the kingdom of Kosala declined. King Sumitra, who regarded himself to be the last Suryavamsha ruler, was defeated by the powerful emperor Mahapadma Nanda of Magadha in 362 BCE. However, he wasn't killed, and fled to Rohtas, located in present-day Bihar.

Ikshvaku and his ancestor Manu are also mentioned in the Bhagavata Purana (Canto 9, Chapter 1),