The go-ahead has been given for the development of a 450-berth marina and 250 apartments at Fishguard.
The scheme, which includes shops and restaurants, has been given outline planning consent by Pembrokeshire County Council.
A report by planning officers said the project's contribution to the local economy was likely to be "significant".
The 80-acre site incorporates a large part of the south side of Fishguard Harbour near Stena Quay, which is the base for ferry services to Rosslare.
A report to Pembrokeshire council's planning committee said the shops, restaurants and cafes would help support the marina and would "supplement" and offer something different to the town centre.
"In addition, the marina and the mix of commercial uses proposed would be a catalyst for regeneration of the local economy which would potentially benefit the existing town centre," said the report.
The main part of the application includes a 450-berth marina; 253 apartments -- 76 one-bed and 177 two-bedrooms; 200 sq m of shops and 500 sq m of financial and professional services; 840 sq m of restaurants and cafe space; a light industrial area, along with a boatyard, workshop and fishing stores.
Two breakwaters to protect the marina are also proposed.