Tan Sri Ariff started his career in 1974 as a law lecturer and subsequently an Associate Professor of the Law Faculty of the University of Malaya before venturing into legal practice as an advocate and solicitor in 1986. He is one of the founding partners of Cheang & Ariff.

In 1993 to 1995, he took leave from legal practice to join the then newly formed Securities Commission of Malaysia and became the first Director of its Market Supervision Department.

In September 2008, he was appointed as a Judicial Commissioner of the High Court of Malaya and later a Judge of the High Court of Malaya in October 2009. In September 2012, he became a Judge of the Court of Appeal.

He returned to Cheang & Ariff as a Consultant after his retirement as a Court of Appeal Judge in early 2015.

Between July 2018 and July 2020, Tan Sri Ariff was elected as the Speaker of the House of Representatives, the Parliament of Malaysia.

He has since re-joined the firm as a consultant.

​Tan Sri Ariff sits on the panel of arbitrators of the Asian International Arbitration Centre and is currently an Adjunct Professor in the School of Law, University Utara Malaysia (Northern University of Malaysia).