The striker has been named in the Republic's starting line-up for the friendly against Romania at Lansdowne Road.
It could be a double celebration as well - Robbie is just two goals away from equalling Niall Quinn's all-time top goalscoring mark of 21 for Ireland.
"I never dreamed when I was younger that I would have so many caps at the age of 23 so naturally I am very much looking forward to this game," said Robbie, who bagged 16 goals for us last season.
"Every game for Ireland is special but obviously the 50th will be particularly special for me.
"I am still only 23 but people see me as an experienced professional which is nice in a way, and I am sure it will stand me and my country in good stead when the World Cup qualifying campaign comes around.
"We have got a lot of young lads coming through who have won only a few caps so it is nice for the few experienced lads to help them out. I have played a lot of games now and people are always expecting me to be scoring goals.
"The goalscoring record is not something I think about every day, if it happens, it happens, but of course it will be nice to get it."
Robbie Keane will win his 50th cap for Ireland tonight at the tender age of 23 - he says it's a dream come true.