No, this is the most common misconception about volatile. It guarantees that accesses occur (aren't optimized away or cached) and aren't reordered relative to other volatile accesses, but it says nothing about atomicity. volatile_counter++ is still a read-modify-write, load, increment, store, and an interrupt landing between the load and store loses an update. On a multi-core system, volatile is also not a memory barrier and won't synchronize data between cores' caches. For atomicity you need a critical section (disabling interrupts around the operation), C11 <stdatomic.h> atomics, or a hardware atomic instruction; for cross-core ordering you need memory barriers. The clean mental split: volatile is for visibility, atomics/critical sections are for atomicity, and shared data often needs both.
C Programming · Interview question
Does volatile make a variable atomic or thread-safe?
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const, volatile & static
Three small keywords with outsized consequences: const for intent, volatile for hardware and ISR-shared data, static for lifetime and linkage, and why volatile is not atomic.