Željko Mrvaljević (Cyrillic: Жељко Мрваљевић; born 25 June 1979) is a Montenegrin former professional footballer who played as a defender, and current football coach. Known for his versatility and tactical awareness, Mrvaljević had an extensive playing career across multiple countries before transitioning into coaching, where he has developed a reputation for developing young talent and providing tactical expertise at the senior level.

Born in Bar, Mrvaljević began his football education in the youth system of local club Mornar. He made his professional debut with Budućnost Podgorica in 1997, where he spent four and a half years establishing himself as a reliable defender in the Montenegrin First League. During his time at Budućnost, he made 35 appearances and scored 4 goals, showcasing his ability to contribute to attack from defensive positions.

Mrvaljević's performances in Montenegro attracted attention from abroad, leading to a move to Poland in 2002. He joined Widzew Łódź, one of Poland's most storied clubs, where he competed in the Ekstraklasa. This marked the beginning of a successful period in Polish football that would span several years.

Over the course of his career in Poland, Mrvaljević became well-known in the Polish leagues, playing for multiple clubs including Kujawiak Włocławek, Zawisza Bydgoszcz, and Unia Janikowo. His consistency and professionalism made him a valued player, accumulating over 100 appearances across various Polish divisions. His adaptability allowed him to perform effectively in different tactical systems and his experience proved valuable to the teams he represented.

After his extended stint in Poland, Mrvaljević returned to Montenegro where he played for several clubs including Mogren, Mornar, and Petrovac. His experience from playing abroad brought valuable knowledge to the Montenegrin league.

At Petrovac, Mrvaljević enjoyed one of the highlights of his playing career, helping the club win the Montenegrin Cup in the 2008–09 season. He made 27 appearances for Petrovac during his first spell with the club, contributing 2 goals, and was an important part of their defensive unit.

Mrvaljević also had a brief spell in Albania with KF Vllaznia Shkodër in 2009–10, adding further international experience to his career. He returned to Petrovac for a second spell from 2012 to 2014, making 38 appearances and scoring 2 goals, before concluding his playing career with Mornar from 2014 to 2015.

Mrvaljević represented Yugoslavia at the U16 level during his youth career.

Following his retirement from professional playing in 2015, Mrvaljević immediately transitioned into coaching, leveraging his extensive playing experience across multiple countries and leagues. His coaching career has been characterized by a combination of youth development work and senior team assistant coaching roles.

Mrvaljević began his coaching career as an assistant coach with Mornar's senior team, where he spent two years working in the Montenegrin First League. This role allowed him to apply his tactical knowledge and playing experience to coaching at the top level of Montenegrin football.

From April 2017 to 2019, he served as assistant coach at Petrovac, a club where he had enjoyed success as a player. His familiarity with the club's culture and his understanding of Montenegrin football made him a valuable addition to the coaching staff.

Demonstrating his versatility as a coach, Mrvaljević moved into youth development, taking on the role of head coach for OFK Grbalj's U16 team from January 2021 to July 2022. In this position, he was responsible for the technical and tactical development of young players, helping to shape the next generation of Montenegrin footballers.

He continued his work in youth football at FC Budva U16 from July 2022 to February 2023, where he served not only as head coach but also as coordinator of junior selections. This expanded role demonstrated his organizational abilities and his commitment to developing comprehensive youth football programs.

In February 2023, Mrvaljević returned to senior team coaching as assistant coach at Petrovac, a position he held until November 2023. He then joined OFK Grbalj's senior team as assistant coach in July 2024, working with the first team in the Montenegrin First League until July 2025.

Since July 2025, Mrvaljević has been serving as assistant coach for Mornar Bar's senior team, returning to the club where he began both his playing career in the youth system and his coaching career. His appointment represents a homecoming to the club from his native city of Bar, bringing his wealth of experience to support the development and success of the first team.

Throughout his coaching career, Mrvaljević has demonstrated a strong focus on defensive organization and tactical discipline, drawing from his own experience as a defender. His work with youth teams has emphasized technical development and football intelligence, while his roles as assistant coach at the senior level have showcased his ability to analyze opponents and contribute to match preparation.

His experience playing in multiple countries and leagues has given him a broad tactical perspective, allowing him to incorporate different footballing philosophies into his coaching approach. Colleagues and players have noted his professionalism, dedication, and ability to communicate effectively with players at all levels.

Petrovac

• Montenegrin Cup: 2008–09^[1]

Mrvaljević was born and raised in Bar, a coastal city in Montenegro. His deep connection to his hometown is reflected in his current role with FK Mornar Bar, the city's main football club. Petrovac

• Montenegrin Cup: 2008–09^[2]

• Željko Mrvaljević at 90minut.pl (in Polish)