are we in the 21st century

Yes, we are in the 21st century. Humanity entered the 21st century on 1 January 2001, and it will last until 31 December 2100, so the current year 2026 falls well inside it.

Why it’s the 21st century

• Centuries are blocks of 100 years, counted starting from year 1, not year 0.

• The 1st century covered years 1–100, the 2nd century 101–200, and so on, which means the 21st century covers 2001–2100.

• A quick rule: take the first two digits of the year and add 1 (20 + 1 = 21 for years like 2024 or 2026), so those years are in the 21st century.

Why some people say “since 2000”

There was popular confusion around whether the new century and millennium began in 2000 or 2001, largely because the year 2000 felt like a symbolic reset.

However, by the strict calendar logic used for the Gregorian calendar, both the 3rd millennium and the 21st century start in 2001, not 2000.

Cultural sense of “21st century”

Beyond the calendar, people sometimes talk about the “real” or “core” 21st century as a cultural era dominated by the internet, smartphones, AI, and social media.

Many commentators and forum users argue that the 2020s—especially after events like the COVID-19 pandemic and rapid AI progress—feel like the moment when the 21st‑century world finally became clearly distinct from the late 20th century.

In short: by the calendar, yes, we are in the 21st century—and by the way life feels, most people would say we definitely are, too.