Beattie joined the Scots from Glasgow Hawks during in the middle of the Championship Cup campaign in December and has gone on to make eight appearances so far this season.
Beattie was formerly of Glasgow Warriors and was part of the Scotland 7s set up where he competed on the World Series. He will now remain in London for another season with the exiles.
The versatile winger is pleased to be staying down in London after enjoying his first spell with the Club.
“I am delighted to be staying on at Scottish for next season. It is a great club to be a part of and a great group of boys too. I am looking forward to cracking on with the rest of the season and hopefully notching up a couple of wins.”
Director of Rugby Dave Morris is happy to be retaining Beattie’s services for another season.
“It is great to have signed Bobby for next season. He has done a very good job for the Club since his arrival in December from Glasgow Hawks. He is a versatile winger who is looking to get better and it will be good to see him develop with a full season at London Scottish next year.”
Updated 17:33 - 9 Apr 2019 by Hugh Barrow