Thomas, formerly of League Two outfit Cheltenham Town, was named Young Player of the Year at Derby for his efforts during the 2017/18 season, making two first team appearances from the substitute's bench in the Rams victories over QPR and Bolton.
The Hammers have long been linked with a move for the winger, and according to Gloucestershire Live, a deal with Derby for the teenager is nearing completion - making him one of Manuel Pellegrini's first signings at the London Stadium.
The 19-year-old joined the Rams from Cheltenham in 2016, progressing through to the fringes of Gary Rowett's first team after a number of impressive performances at reserve team level. He could be set to follow Rowett out of Pride Park however, with the former Birmingham boss leaving to join Stoke on a three-year deal earlier this week.
If we are meant to blooding youth next season, selling Luke Thomas would be foolish. Young player of the year and a real prospect.— Derby Retweets (@DerbyRetweets) May 23, 2018
The winger impressed on a loan spell with Gloucester City during the 2016/17 National League North season, continuing in the same vein for Derby's Premier League 2 side this year. Thomas made 17 appearances during the campaign, scoring six times and assisting one.
Any potential move for Thomas will see Cheltenham receive a 15% sell on fee, which as it stands, could pocket the Robins up to £180,000.
The Hammers meanwhile have confirmed the departures of former Manchester United defender Patrice Evra, as well as fan favourite James Collins, who departs the London Stadium after 10 years service - spread over two separate spells at the club.