Muslim began his career with playing for Harimau Muda A. He is the captain of Harimau Muda A. Muslim Ahmad is a Malaysian national football player. He has played for the Malaysia national football team, and in summer 2009 he played twice against Manchester United in their pre season tour of the Far East. Muslim and 25 other players, who play for Harimau Muda A, were chosen to participate in a training camp in Slovakia. During his time in the training camp, Muslim and his teammate, Gary Steven Robbat were given a trial from the Slovakian team FC ViOn Zlaté Moravce on 30 March. FC ViOn Zlaté Moravce Coach Ľubomír Moravčík Promised Muslim and Gary a professional contract for the next 2010–2011 season. Later, FC ViOn Zlaté Moravce lost interest in Muslim and Gary due to internal problems in the club. In November 2010, Muslim was called up to the Malaysia national squad by coach K. Rajagopal for the 2010 AFF Suzuki Cup. Malaysia won the 2010 AFF Suzuki Cup title for the first time in their history.
Club career
Terengganu FA
Muslim Ahmad left Harimau Muda A to return to his home team Terengganu as the defender prepares to combine the chase for domestic honours with a glittering international career. Having established himself with the national team, the 22-year-old Muslim felt the time is right to leave the sheltered life at Wisma FAM and embark on a new path in his career. Muslim, who has two Sea Games gold medals and an AFF Cup winners' medal in his collection, now aims to help FA Cup winners Terengganu advance past the first round of the AFC Cup, win the Super League and Malaysia Cup when the new season starts. Muslim made his first league debut against Perak FA. The match ended with Terengganu suffer a narrow defeat 1–0. Muslim plays his first AFC Cup match against Vietnam side, Sông Lam Nghệ An F.C.Terengganu marks the first win on the AFC Cup debut with 1–0 wins. On 22 August 2012, Muslim made his Malaysia Cup debut against Kelantan FA. Muslim help Terengganu to open their campaign with a shocking victory 2–0. On 19 September 2012, Muslim left Terengganu FA after being released by the club.
On 4 November 2012, Malaysia Super League side, Johor confirmed that Muslim would join the club. He make his debut against Pelita Bandung Raya in a friendly match. Muslim scored in his debut after being assisted by teammate Simone Del Nero. He play another friendly game against Woodlands Wellington FC with 5–1 win.
On 5 December 2015, he was revealed as Kelantan new player
International career
Muslim was only 19 when made his senior international debut in 2009. His first tournament action was at 2009 Sea Games. Muslim helps Malaysia to win their fifth Sea Games gold medal. Muslim also played at 2010 Asia Games. Muslim led Malaysia to qualify for the second round of the 2010 Asia Games as one of the best four third-placed teams after a lapse of 32 years. Muslim was called by Malaysia coach, Dato K. Rajagopal to play at 2010 AFF Suzuki Cup. Malaysia won the 2010 AFF Suzuki Cup title for the first time in their history under the management of Dato K. Rajagopal.