Lightbourne - 6'2" - has found the net just four times this season for his club Macclesfield from 23 starts and 7 sub appearances.
He said after completing his move to Boothferry Park: "I got a call from the chairman on Tuesday asking me if I'd like to come to Hull City on loan until the end of the season.
"In my current position it seemed like a good option and hopefully I can help the team push on for promotion and score a few goals along the way.
"I had been playing regularly for Macclesfield at the start of the season but then I got injured and with new management coming in my situation has changed.
"But in football that's something you have to accept and I'm just grateful that this new opportunity has presented itself."
Lightbourne began his career at Scarborough in 1992, moving to Walsall 9 months later on a free transfer. He scored 86 goals for the Saddlers in almost 200 appearances, before Premiership side Coventry City shelled out £500,000 for him in 1997.
He struggled to make an impact at Highfield Road, but after scoring 3 in 5 for Fulham on loan Stoke City moved for him.
Coventry recaptured the £0.5million they paid for him, and he had a reasonable spell with the Potters, scoring 25 goals in 100 starts.
He had short spells with Swindon and Cardiff on loan last season before moving to Macclesfield in the summer on a free transfer.