Yes. Tonks calls him it directly at least twice in The Advance Guard, OotP.
"Nice one, Mad-Eye," said Tonks appreciatively
"We're not going through clouds!" shouted Tonks angrily, "we'll get soaked, Mad-Eye!"
We know they're close, and she's his protégée at the Ministry, but I doubt he thinks it's only her nickname for him. She also uses it around other people, which indicates it isn't just between the two of them, and others are expected to know it.
Sirius also calls him that directly at least once too.
Sirius had just said, "What's that you've got there, Mad-Eye?" and Moody had turned towards him.
The Woes of Mrs Weasley, OotP
In GoF, although he isn't actually himself for it (so the real Moody wouldn't know from this source), Rita Skeeter refers to him as 'Mad-Eye' in one of her articles.
"In September of this year, he hired Alastor "Mad-Eye" Moody, the notoriously jinx-happy ex-Auror... Mad-Eye Moody, however, looks responsible and kindly"
Dumbledore's Giant Mistake, Daily Prophet
Padfoot Returns, GoF
She is often rude about the subjects of her articles, but she is using the name as though it's common knowledge. As The Daily Prophet is the wizarding newspaper with the largest circulation, it wouldn't be surprising that Moody would read it.