Yes. Many Buddhists drink coffee and tea. Buddhism has no universal prohibition on caffeine. The ethical rule most relevant to substances is the Fifth Precept, which concerns intoxicants that lead to heedlessness, and most Buddhist communities do not classify ordinary coffee as an intoxicant in that sense.
Coffee is not generally forbidden
Coffee is part of ordinary life in many Buddhist-majority or historically Buddhist societies. Lay Buddhists, monks, nuns, and meditation practitioners may drink coffee depending on local custom and the rules of a particular monastery.
Some monasteries limit caffeine for health, simplicity, retreat discipline, or sleep quality, but such rules are local rather than a worldwide Buddhist commandment.
The Fifth Precept
The Fifth Precept asks lay Buddhists to refrain from intoxicating drinks and drugs that lead to carelessness or heedlessness. It is most clearly applied to alcohol and recreational intoxicants.
Caffeine stimulates alertness rather than producing drunkenness, so coffee is normally treated differently. That said, a person can still examine whether dependence, overuse, anxiety, or sleep disruption is undermining mindfulness and health.
Monastic practice
Buddhist monastic rules vary. In some Theravāda contexts, monks do not eat solid food after noon but may consume certain allowable drinks. Whether coffee, milk, sugar, or other additions are permitted can depend on local interpretation and the exact form of the drink.
Retreat centers may also establish stricter schedules than everyday lay life.
Coffee and meditation
Some practitioners find a small amount of caffeine helps alertness during early meditation. Others find that it increases restlessness, heart rate, or anxiety. Buddhism does not require one universal answer because the effect differs among individuals.
Mindful consumption means paying attention to motivation and result: Is the drink simply enjoyable? Is it supporting wakefulness? Is it becoming compulsive? Is it disturbing sleep or concentration?
Voluntary renunciation
A Buddhist may choose to give up coffee for a retreat, observance period, health reason, or practice of simplicity. Voluntary renunciation can reveal habits and attachments, but abstaining from coffee is not a standard requirement for being Buddhist.
The practical answer
Buddhists can drink coffee. The Fifth Precept is primarily concerned with heedlessness-producing intoxicants, and ordinary caffeine is not generally treated the same way as alcohol.
Specific monasteries or retreats may have their own rules, so participants should follow the discipline of the community they are visiting.
