Adrianne Palicki and Scott Grimes have got engaged.

The 'Orville' co-stars took to social media to confirm they are to marry, and the 'John Wick' actress showed off her engagement ring in a selfie.

Adrianne - who plays Commander Kelly Grayson in the Fox show - wrote on Twitter: ''So happy to spend my life with you @ScottGrimes #ido #iloveyou (sic)''

The 'Agents of S.H.I.E.L.D.' star shared a black and white picture of herself and her husband-to-be sitting on a sofa, with both sporting huge grins.

However, some fans were confused as to whether they were celebrating their engagement or in fact their marriage after Adrianne, 35, hashtagged the caption ''I do''.

But they were inundated with messages of congratulations from fellow stars and supporters.

Former 'The Bachelor' star Bob Guiney wrote: ''YES!!! Congratulations to both of you! Couldn't be happier for you. (sic)''

Scott - who plays Lieutenant Gordon Malloy in sci-fi comedy-drama 'The Orville' - replied: ''yes you could (sic)''

'The Thinning' actor Michael Traynor tweeted: ''Wild Congratulations from your friendly neighborhood #KrillCaptain!! (sic)''

Adrianne was previously engaged to stuntman Jackson Spidell, after meeting him on the set of 2014 movie 'John Wick', in which she starred opposite Keanu Reeves.

Scott, 47, was married to Dawn Bailey-Grimes - with whom he has a daughter, Madison, 19, and son Jackson, 17 - from 1997 to 2007.

He later married Megan Moore in 2011, but she filed for divorce in October 2017.

The pair star opposite Seth Macfarlane in 'The Orville'.