The Teessiders dropped to fourth in the Sky Bet Championship with the goalless stalemate and will face the fifth-placed Bees in the play-off semi-finals.
The last league game of the league campaign was very much an anti-climax in front of a bumper Riverside crowd, with the 33,381 attendance being Boro’s biggest of the season.
But the entertainment did not live up to the billing as both sides seemed happy to play out the draw.
The buzzing early atmosphere was soon dampened when Brighton threatened to spoil the Boro party early on when they forced a corner. Boro failed to clear Dale Stephens’ set-piece and both Gordon Greer and Lewis Dunk fluffed their lines in front of goal.
Boro looked laboured and struggled to find their passing game but they nearly took the lead in the 16th minute when Kike controlled well before releasing Albert Adomah, whose strong shot was well saved by Christian Walton.
The home side produced a fine move mid-way through the first half when Dutch full-back Dwight Tiendalli did well to control an awkward ball on the right wing, pulled back to Lee Tomlin and he chipped into the box but Adam Clayton could not connect fully with his effort.
Tiendalli was at the centre of another silky move minutes later when he played in Kike and the Spaniard laid off for Adomah, but his shot was deflected wide.
Boro should have scored ahead shortly after the half-hour when left-back Fernando Amorebieta robbed ex-Boro defender Joe Bennett on the half-way line and charged at Brighton before pulling back to Kike, but his first touch took him away from goal and the Seagulls were able to clear.
The last 15 minutes of the first half resembled a training session, with neither side willing to press and both seemingly happy with a point.
But Boro looked a little brighter after the break and five minutes into the second half Tomlin laid off for Adam Forshaw to hit a strong shot but it was straight at Walton and he held it comfortably.
They threatened again a few minutes later when Grant Leadbitter whipped in a corner and Kike met it first time but his flicked shot flashed well wide.
Brighton should have taken the lead with 20 minutes to go when former Sunderland defender Greg Halford broke down the wing and crossed into the box, but Chris O’Grady blazed over the bar from close range.
Boro had a great chance to take the lead in the 80th minute when the ball fell to Kike just in front of goal but his scuffed effort was cleared by Brighton.
The home side did not do enough to press for a late winner and both sides were happy to take the point.