Luckily and fortunately both mean “because of good luck,” but they feel slightly different in tone.

Word Meaning Tone Example
Luckily Something good happened by chance More casual and everyday “Luckily, I found my keys before leaving.”
Fortunately Something good happened, often preventing a bad result More formal and polished “Fortunately, no one was injured in the accident.”

Luckily is more conversational.

Example: “Luckily, the rain stopped before the game started.”

Fortunately sounds more professional, formal, or written.

Example: “Fortunately, the issue was resolved before the deadline.”

A simple way to remember it:

Luckily sounds more personal and casual.

Fortunately sounds more formal and serious.

Both are often interchangeable:

“Luckily, we arrived on time.”

“Fortunately, we arrived on time.”

The meaning is almost the same, but fortunately sounds a little more polished.