Eluru (/ˈeɪluːrʊ/ AY-loo-roo) is a city and the district headquarters of Eluru district in the Indian state of Andhra Pradesh. It is one of the 14 municipal corporations in the state and the mandal headquarters of Eluru mandal in the Eluru revenue division. Situated on the banks of the Tammileru River, Eluru is strategically positioned in the southeastern part of Andhra Pradesh. It was historically known as Helapuri. As of 2011^[update] Census of India, the city had a population of 214,414, where as Eluru Urban Development Authority has a population around 2,760,160, reflecting its status as a major urban centre. The city's historical significance dates back to the second century CE, with evidence of its ancient roots found in various archaeological sites and historical records. Eluru was a prominent town under the rule of the Qutub Shahis, who governed the region in the 16th century. It came under the control of the Mughal Empire in the 17th century as the empire expanded its influence across South India. The town later became part of the Nawab of Hyderabad's dominions in the 18th century. During British India, Eluru was incorporated into the Madras Presidency and made capital for Northern Circars in the early 19th century. The British established administrative and infrastructural developments in the town, shaping its modern identity.

The city came into headlines after the outbreak in 2020, which was a significant event that drew national attention. The incident involved a mysterious illness that affected hundreds of people, leading to widespread concern and a major public health response. It is situated in the Krishna River Delta region, and is known for its fertile agricultural lands. The city is intersected by various rivers and canals. Kolleru Lake, the largest freshwater lake in inland India is located within a few kilometers from the city.

Eluru has made significant contributions to Indian film and arts through several notable personalities like L. V. Prasad, Silk Smitha, Sekhar Kammula etc. The city plays a crucial role in regional commerce, Eluru is renowned primarily for its pile carpets, though it also manufactures textiles and leather goods. Additionally, the city serves as a key trade hub for fresh water fish, rice, oilseeds, tobacco, and sugar. Located on the Golden Quadrilateral, the city is well-connected by road, rail, and airways. Alluri Sitarama Raju Stadium, situated in Eluru, is a prominent sports venue named after the celebrated Indian freedom fighter Alluri Sitarama Raju. Eluru's educational landscape includes several notable institutions, such as ASRAM Medical college, Sir C.R. Reddy Educational Institutions, etc, which contribute to the city's reputation as a centre for learning.

The city was part of the Vengi Kingdom and served as the capital during the Buddhist kingdom's rule, where it was known as 'Helapuri'. It was also called Erla Uru before being renamed Ellore by the British. To avoid confusion with Vellore, which had a similar pronunciation during the Nizam rule, Ellore was referred to as Uppu Ellore (i.e. Salt Ellore), while Vellore was called Ra Vellore or Raya Vellore.

The history of Eluru dates back to the second century CE and has great prominence in the history of Andhra. Vengi near Eluru was the capital of Andhra from the second century to the twelfth century, ruled by Salankayanas, Vishnukudinas, and Eastern Chalukyas. Vengi was the capital city of Andhradesa for more years than any other city in Andhra Pradesh.

The Salankayanas ruled from the third to the fifth century CE, with their domain centred around the Vengi region and Eluru serving as their capital. Known as Šalaňkayana after their Gotra name, they were feudatories of the Ikshvakus. The historical significance of the Salankayanas is highlighted by the inscription of their first known king, Devavarman, in Eluru (Ellore), where he recorded performing the Ashvamedha sacrifice to mark his successful establishment of the kingdom. The Salankayanas are considered one of the elusive kingdoms of Andhra, with their timeline corroborated by references in the Samudra Gupta inscription mentioning Hastivarman of Vengi.

In the late fifth century, the Salankayanas were conquered by Madhavarma II of the Vishnukundinas. During the reign of Madhava Varma the Great, they became independent and conquered coastal Andhra from the Salankayanas and might have shifted their capital to a place in coastal Andhra. Eluru was a major city of the Vishnukundinas. Vishnukundin reign might be fixed between the end of the Salankayana and the rise of the Eastern Chalukyan power in 624 AD.

Eastern Chalukyas, or Chalukyas of Vengi, were a dynasty of South India whose kingdom was in the present day Andhra Pradesh. Their capital was Vengi near Eluru and their dynasty lasted around 500 years from the seventh century until 1130 AD, when the Vengi kingdom merged with the Chola empire. The Vengi kingdom continued to be ruled by the Eastern Chalukyas (Eastern Chalukyan kings) under the protection of the Chola empire until 1189 AD, when the kingdom succumbed to the Hoysalas. They had their capital originally at Vengi, now Pedavegi, near Eluru and was later changed to Rajamahendravaram (Rajahmundry).