Which is correct 'It was just Tommy and I' or 'It was just Tommy and me'?

Answer 1

"It was just Tommy and I."

This is a simple answer that requires explanation.

The subjective form is "I" and the objective form is "me." So it would be grammatically correct to use the pronouns I, he, and we as subject complement. But this is almost never done.

Examples:

"It was I" seems familiar enough and as common in use as "it was me."

"It was just I" (It was only I) has a stranger sound, and "me" is almost always used informally. However, if you were to add a phrase such as "who ate the pie," then the subjective form becomes unmistakable.

"It was just Tommy and I who ate the pie." (Tommy ate the pie. I ate the pie.)

(for more on possible exceptions, see the related link)