`encoding/csv` reads UTF-8 BOM.

main.go

package main

import (
	"encoding/csv"
	"fmt"
	"log"
	"os"
)

func main() {
	file, err := os.Open("utf8bom.csv")
	if err != nil {
		log.Fatal(err)
	}
	defer file.Close()

	reader := csv.NewReader(file)
	headers, err := reader.Read()
	if err != nil {
		log.Fatal(err)
	}

	fmt.Printf("%X\n", "col1")     // =>       636F6C31
	fmt.Printf("%X\n", headers[0]) // => EFBBBF636F6C31
}

utf8bom.csv