The forward joined Rovers in 2012 and was made captain ahead of the start of the 2019 campaign.
He briefly left the club in 2015 but returned in 2016 and has made a total of 165 appearances in his seven seasons with Featherstone.
He has scored 32 tries for Rovers and began his professional career at Yorkshire neighbours Dewsbury Rams in 2009.
"I'm happy to stay here," said Lockwood.
"I'm enjoying my rugby and I like playing under Ryan Carr. We have a really good squad and we're all enjoying it at the minute.
"We had a bit of a slow start, but over the last couple of months we have really gelled and I think there's some outstanding players here.
"There's good competition for places now."
Head coach Ryan Carr expressed his delight, adding: "He's been a big part of what we have done here, he has very high standards and he's been vital this season.
"He leads from the front and the we're happy he has continued his stay with the club, it is a positive for sure."
Featherstone Rovers CEO Davide Longo was similarly pleased, and said: "James is a fantastic servant to the club and always plays tough and leads by example.
"He’s having a great season as captain and thoroughly deserves another two years at the club."