Nikola Milojevic

As a junior, Milojević was a prodigious player who won several youth tournaments. He won his first title, the U14 Jug Open, on 25 May 2008, when he was still one month short of his 13th birthday. Between July and November 2008, Milojević reached five U14 finals in a row, winning three and losing two.

In 2009, Milojević dominated the U14 circuit in the Tennis Europe Junior Tour, starting off the season by winning a national title at the indoor championship held in Novi Sad, which was followed by a Category 1 title in Bolton. He then collected two of the most prestigious trophies of the year at Petits As and the European Junior Championships at Pilsen, beating Borna Ćorić and Kyle Edmund, respectively, in the finals. He also won titles in Maia (Portugal) and Livorno (Italy). He remained undefeated in his age group (Under 14), both on the domestic and world stage, until six months after his debut in the U14 circuit.

Before he turned 14, Milojević started competing in the ITF Junior Circuit in the under-18 category. In his first three tournaments, he reached the quarterfinals in all of them, including a semifinal in Riyadh, Saudi Arabia, in November 2009.

In 2012, Milojević won five ITF titles across all four surfaces, winning in Malaysia and Manila on hardcourts, in Halle on grass, Nagoya on carpet, and in Mexico City on clay. He then kickstarted 2013 by winning the Copa del Cafe in Costa Rica, beating Tommy Mylnikov in the final. This triumph allowed him to become the world's No. 1 in the ITF Junior rankings, thus becoming the first Serbian to reach such a feat since Janko Tipsarević.

Milojević was a fifth player on a Serbian Davis Cup team in the first round tie against United States in the 2010 Davis Cup as well as a first round tie against Switzerland in 2014 and didn't play in any match.

Milojević made his ATP main draw debut as a wildcard at 2014 Düsseldorf Open, where he defeated Mirza Bašić in the first round before losing to eventual finalist, Ivo Karlović, in the second round.

He was also invited for a semifinal clash against France in 2017, but instead chose to play in a Challenger tournament in order to improve his ATP ranking. He reached the top 150 on 2 October 2017.

In February 2018, he finally made his Davis Cup debut, partnered with another debutant, Miljan Zekić, in a doubles match against the US, losing 7–6⁽³⁾, 2–6, 5–7, 4–6 in the first round.

In June 2018, Milojević won his first Challenger title in Fergana, Uzbekistan.

Milojević partnered with Danilo Petrović for the 2018 Davis Cup World Group play-offs vs. India in September. They defeated Rohan Bopanna/Saketh Myneni in straight sets to help secure Serbia a decisive 3–0 lead after second day's play. (Serbia eventually won the tie 4–0)

In August 2019, he won his third Challenger title at the 2019 Svijany Open in Liberec, Czechia.

In January 2020, he was part of Serbian team that won the Inaugural ATP Cup by defeating Spain in the final.

In September 2020, Milojević reached the second round on his debut as a qualifier in a Grand Slam main draw at the 2020 French Open, where he won his first match against fellow Serbian Filip Krajinović in four sets 6–4, 3–6, 6–3, 6–1.

After winning his third Challenger title at the 2021 Zadar Open in Croatia by defeating Bulgarian Dimitar Kuzmanov, Milojević reached his best career-high ranking of No. 129 on 5 April 2021.

In January, Milojević qualified into the main draw of the 2022 Australian Open for the first time at this Major, but lost to Mackenzie McDonald in the opening round. After the Australian tour, he reached the quarterfinals as a lucky loser at the Córdoba Open where he lost to Juan Ignacio Londero. As a result, he reached the top 125 on 21 February 2022.