Chalobah was unable to break into the first team at Burnley and returned to Chelsea when the loan ended on 2 January 2015. During his time with Burnley, Chalobah only made four substitute appearances.
On 22 January 2015, Chalobah joined Championship club Reading on loan for the remainder of the season. On 24 January 2015, Chalobah made his debut in a FA Cup match against Cardiff City, as the team won 2–1 to advance into the fifth round. Three days later, Chalobah made his league debut against Millwall.
On 31 January 2015, in his home debut, Chalobah scored the second of a 2–0 victory over Sheffield Wednesday, helping the Royals to their first league win since December. During his time with Reading, Chalobah made a total of 20 appearances and started in every appearance.
On 1 September 2015, Italian club Napoli confirmed that Chalobah had joined the club on a season long loan from Chelsea. On 1 October 2015, Chalobah made his Napoli debut in a UEFA Europa League tie against Legia Warsaw. The fixture resulted in a 2–0 victory for the Italian team, with Chalobah featuring for five minutes after replacing Allan. On 26 November 2015, Chalobah was given his first Napoli start in a 1–0 victory over Club Brugge in the UEFA Europa League group stage tie. On 10 December 2015, Chalobah scored his first Napoli goal in a 5–2 win over Legia Warsaw, scoring Napoli's first. On 6 January 2016, Chalobah finally made his Serie A debut in a 2–1 victory against Torino, replacing Marek Hamšík in the 89th minute.