The school teaches subjects towards the International General Certificate of Secondary Education and GCSE qualifications, including English Language and English Literature, Mathematics, Sciences, and Languages (at least one of French, German, Spanish, or Latin). Aside from compulsory subjects, students are able to study History, Geography, Classics, Religious Studies, Music, Art, Computer Science and Design Technology (specialising in Electronics, Resistant Materials and Textiles). Some GCSEs can be studied outside of curriculum time, including General Studies and Russian.

Yarm Sixth Form requires all students to take at least 3 A-Level subjects (Four A-Levels can be taken if Further Mathematics is included with Mathematics) and includes Extended Project Qualification in the curriculum. A-levels are taken in Humanities, sciences, creative arts and social sciences

In 2012 the school was listed for A-levels, as the 20th most successful independent school in the country by The Independent. In 2019 Yarm School was recognised as the top performing school in Teesside and County Durham for its A-level results by The Gazette.

Sports include rowing, rugby, cricket, hockey, netball, rounders, football, tennis, kayaking, climbing and canoeing; partaking in sport or outdoor education is compulsory.

Pupils help to raise money for their designated house charities. These charities can be local, national or international. Each house typically raises over £2,000 per year through a variety of fundraising activities.
In July 2009 a team of cyclists from the school won the over-16 category of the British Schools Cycling Association National 10 miles (16.1 km) Time Trial Championships. The school has a rugby tradition and maintains links with the 'Yarm Old Boys' rugby team. On 23 March 2013 the 1st XV won the U18 Daily Mail Vase against Felsted School 17–15 at Twickenham.

The school also has a competition boat club, the Yarm School Boat Club. In 2022 it won 11 events over the two-day Durham Regatta and has performed successfully at the National Schools' Regatta, with a bronze medal in 2014 with the J15 1st 8+. Most recently, Yarm School also won a bronze in the J15 4+ in the 2022 National Schools Regatta. It has also been represented at Henley Royal Regatta. There have been impressive results at national events like Henley Women's Regatta, with a semifinal in the J16 4+ in 2021. The school has been to international events, such as the Royal Canadian Henley Regatta and the Head of the Lagan in Belfast, Northern Ireland. It regularly produces high-performance athletes, most notably Kat Copeland, Olympic Gold medallist.
The school has an outdoor education department which organises games, activities (such as canoeing, kayaking, fire building and bushcraft) and school expeditions.
The cadets represent Yarm School parade on Armistice Day in front of Yarm Town Hall, to commemorate the lives of service personnel who died in the Second Boer War, First World War, Second World War and the Korean War.

The school is arranged into four houses, each with its own housemaster or housemistress and tutor team. Houses have their own colours and compete at an inter-house level in sports, chess, drama and debate. Each house is named after prominent British saints associated with the North East of England: Aidan, Bede, Cuthbert and Oswald. There are five Senior School year groups, plus a Lower and Upper Sixth.