Robinson made seven appearances for the Vixens last year and has also featured for England at Under-17 level.
She's the second young player who Hope Powell has added to her squad, with 21-year-old goalkeeper Katie Startup joining the seagulls last week.
The south-coast side started their pre-season training on Monday, with the exact date for the return of the Women's Super League currently unknown, although the FA's target start date is the weekend of the 5th of September.
'I can't wait to learn and improve'
Speaking to Brightonandhovealbion.com when her transfer was announced, Robinson spoke of her excitement to start playing for Brighton:
“I am absolutely delighted to be joining Brighton. It’s a great club and I am really looking forward to working with [head coach] Hope Powell, the staff and players, and I can’t wait to get going.
“Hope has got so much experience. She’s a great manager and I can’t wait to learn and improve under her.
“I play on the wing or as a number nine. I try and bring pace and be creative in one-v-one situations. I am very direct - I want to go forward as quickly as possible.”
'A versatile player'
When the transfer was announced, Brighton boss Hope Powell spoke of how Katie Robinson's abilities as a forward will help the seagulls:
“To break into the WSL as Katie did for Bristol City last season was quite an achievement for a 17-year-old,” she said.
“She’s a versatile player because she plays up front or out wide and offers a goal threat. We’re looking forward to see how she develops, and I am sure she will want to be pushing for the first team squad as soon as the season starts.”