| Jack Sinclair | |
| Position: | Lock / Centre / Second-row |
| Teama: | New South Wales |
| Yearastart: | 1961 |
| Appearancesa: | 2 |
| Triesa: | 0 |
| Goalsa: | 0 |
| Fieldgoalsa: | 0 |
| Pointsa: | 0 |
| Teamb: | Australia |
| Yearbstart: | 1961 |
| Appearancesb: | 1 |
| Triesb: | 0 |
| Goalsb: | 0 |
| Fieldgoalsb: | 0 |
| Pointsb: | 0 |
| Club1: | Balmain Tigers |
| Year1start: | 1957 |
| Year1end: | 60 |
| Appearances1: | 47 |
| Tries1: | 6 |
| Goals1: | 0 |
| Fieldgoals1: | 0 |
| Points1: | 18 |
| Club2: | Manly Warringah |
| Year2start: | 1961 |
| Year2end: | 64 |
| Appearances2: | 50 |
| Tries2: | 13 |
| Goals2: | 0 |
| Fieldgoals2: | 0 |
| Points2: | 39 |
Jack Sinclair (1935–2006) was an Australian rugby league player.[1]
Sinclair competed in first-grade for Balmain from 1957 to 1960, initially as a centre, before getting later games as both a second-rower and lock. He toured New Zealand with Australia in 1961 and was their lock in the 1st Test, which he played through with a fractured wrist. From 1961 to 1964, Sinclair played for Manly Warringah.[2]
In 1965, Sinclair joined Lithgow as captain-coach.[3]