What to Wear to a Thesis Defense or Viva

The principle: make clothing a non-factor

Your examiners are there to assess five or more years of research. They are not assessing your outfit. The practical aim is to wear something that fades into the background — clothes that are a level or two more formal than your normal day-to-day dress in that department, comfortable enough that you stop thinking about them ten minutes in.

A useful benchmark: dress roughly as you would for a job interview in your field. That typically means collared shirt, smart trousers or a skirt, and closed shoes for most STEM and humanities departments. A blazer or jacket works well because it reads as composed without being stiff, and you can take it off if the room is warm.

Comfort carries real weight here. If you will be standing at a podium for a 20-minute presentation and then sitting for two hours of questioning, shoes that hurt by hour one are a genuine problem. Break in any new shoes before the day, or wear ones you already trust.

Closed viva (UK) vs. public defense (US and Europe)

In the UK, the viva is a closed oral examination: you, typically two examiners, and sometimes an independent chair. No audience. That changes the calculus slightly — there is less performance to it, and the register is more like a senior interview than a conference talk. Smart-casual is solidly appropriate. A full suit is fine but not required at most institutions.

In the US and much of continental Europe, the defense often begins with a public presentation open to department members, colleagues, and sometimes family. With an audience present, stepping up formality by one notch makes sense — a suit jacket or blazer, a dress, a tailored shirt. It is still not a black-tie event, but you are effectively giving a public academic talk before the closed committee session, and your clothing should reflect that.

In both formats, look at photos from recent defenses in your department, or ask a postdoc or recently-graduated peer. That gives you a real data point rather than a general principle.

Practical specifics for the day

• Layers: exam rooms vary wildly in temperature. A removable layer — a cardigan, blazer, or light jacket — lets you adjust without making it an event.
• Sitting for long periods: avoid anything tight around the waist or restrictive across the shoulders. You will shift in your chair repeatedly across a multi-hour exam.
• Colour: darker, mid-tone colours tend to read as composed on camera and in person. Bright patterns or high contrast can be distracting in a video call grid. Neither is a rule — just a consideration.
• New clothes on the day: not recommended. Wear something you have put on before and know feels right. The defense is not the occasion to trial a new fit.

For online vivas and virtual defenses, the top half is what your examiners see, so direct your attention there. A collared shirt or blouse against a reasonably neutral background is sufficient. Test your camera the day before — lighting changes how colours and fabric read, and what looks fine in the mirror can look washed out or overly dark on screen. A light source in front of you (not behind) makes a significant difference.

What you do not need to worry about

Discipline norms vary more than general advice suggests. A fine arts or design department has a different ambient dress register to a clinical medicine or law department. Neither is wrong. The right comparison is your specific department — not a generic idea of what a PhD candidate looks like.

Cultural and religious attire is entirely appropriate. There is no requirement to dress in a particular Western professional style; what matters is that the clothing reads as considered for the occasion within your own context. If your normal professional or formal dress includes a hijab, turban, traditional garments, or any other culturally significant clothing, wear it. No reasonable examiner treats this as anything other than appropriate.

If you have any uncertainty about your specific institution, email your doctoral college or text your supervisor. A quick question asked three days before removes the guesswork entirely and frees up mental space for the work that actually determines the outcome.